JPS637508A - Manufacture of thin film magnetic head - Google Patents

Abstract

PURPOSE:To improve an electromagnetic conversion characteristic and a yield, or processing accuracy, by performing etching of prescribed depth on the inside of a track width regulating groove, and afterwards performing the filming, and the flat grinding of a lower magnetic film, and after that forming a coil conductor, and an upper magnetic film. CONSTITUTION:A nonmagnetic film 2 is formed adhesively on a substrate 1, and a track width regulating groove 3 is form by performing the etching of the nonmagnetic film 2. The groove 3 is formed as a width Tw equal to a track width set by setting a distance between wall planes 3a, 3a as a head, in the neighborhood of a plane 4 equivalent to the oppositely installed plane of a magnetic recording medium. An oblique plane 5 which inclines with a prescribed angle is formed at the inside of the groove 3, and the oblique plane 5, and the wall plane 3a constitute a groove 6, and furthermore, a lower magnetic film 7 is formed adhesively over the whole plane of the nonmagnetic film 2. The flat grinding is applied on the nonmagnetic film 2 until a desired core thickness can be obtained, and a coil conductor 11, a drawing electrode 13, and an upper magnetic film 14 are laminated on an upper plane 8 in order through insulating films 10 and 12, thereby, a magnetic circuit part can be formed. In this way, it is possible to eliminate the short-circuit, etc., of the coil conductor 11, and also, to improve the yield, and in addition, the reliability of the head, or the electromagnetic conversion characteristic can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing an electromagnetic induction type thin film magnetic head mounted on a drive device such as a video tape recorder (VTR), for example.

[Summary of the invention]

In manufacturing a thin film magnetic head, the present invention forms a track width regulating groove having a width equal to the track width on a substrate by reactive ion etching, and furthermore, the inner side of the trunk width regulating groove is formed into an inclined surface. Etching is performed to a predetermined thickness by taper etching, then a lower magnetic film is deposited, surface grinding is performed, and after a while, a coil conductor and an upper magnetic film are formed by photolithography. This aims to eliminate crosstalk from adjacent tracks, improve electromagnetic conversion characteristics and reliability, and improve yield and processing accuracy.

C. Prior Art] In the field of magnetic recording, magnetic recording media are trending toward higher coercive force as recording density increases, and recording and reproducing wavelengths are also becoming shorter. Therefore, in the case of magnetic heads, it is necessary to respond to the above-mentioned high-density recording by using high saturation magnetic flux density materials such as Fe-A1'-5i alloys for the magnetic core, and by making gear knobs narrower. I'm trying.

Under such circumstances, it is well known that a thin film magnetic head manufactured using a technique similar to the half-quad manufacturing process has been developed and put into practical use.

- In general, the above-mentioned thin film magnetic head has a lower magnetic film formed on a flat substrate made of, for example, Mn-Zn ferrite, and further a coil conductor and a magnetic conductor are formed on the lower magnetic film via an insulating film. It is manufactured by sequentially laminating films using photolithography technology, and is configured to form a closed magnetic path by the cooperation of the lower magnetic film and the upper magnetic film.

Incidentally, in the thin film magnetic head described above, the trunk width is regulated by patterning the upper magnetic film or the lower magnetic film, but various improvements remain.

In other words, when the above-mentioned track width regulation is performed using the upper magnetic film, the upper magnetic film is separated so as to match the track width, whereas the lower magnetic film is formed by a series of films. Therefore, in a multi-channel thin film 6N air head, etc., energy talk during off-trunk becomes a problem. This is due to the reproduction of signals from the lower magnetic film other than the track forming part (so-called pseudo signals), and although it does not have much effect on recording and reproduction of analog signals, the error rate increases when recording and reproduction of digital signals. It deteriorates and is not desirable.

On the other hand, there is a method of regulating the track width using the lower magnetic film, but in this case, a large step is created between the trunks after the lower magnetic film is formed, which makes it difficult to ensure the patterning accuracy of the coil conductor and the upper magnetic film. It has become difficult to do so. In some cases, coil conductors may be short-circuited, or resist may remain between the trunks, causing major problems in terms of electromagnetic conversion characteristics and reliability.

Therefore, in order to solve the above-mentioned problems, the applicant of the present invention proposed in Japanese Patent Application No. 4692/1987 that the trunk width is regulated by a groove formed in the non-magnetic oxide film on the substrate, and that We proposed a method to obtain a thin-film magnetic head by filling a lower magnetic film and forming a coil conductor and an upper magnetic film on the lower magnetic film via an insulating film.

[Problem that the invention seeks to solve]

By the way, the above groove is formed by reactive ion etching (Reac
It is formed using a technique called tive ton etching (hereinafter abbreviated as RIE). As shown in FIG.
52) because it advances in the direction perpendicular to the upper surface (52a), so l
The wall surface (53a) of (53) is the above-mentioned upper surface (52a)
It is formed perpendicularly to the For this reason, the groove (53)
has a rectangular shape when viewed from the surface (58) corresponding to the surface facing the magnetic recording medium.

Therefore, after filling the groove (53) with the lower magnetic film (54) by sputtering, surface grinding is performed until a predetermined core thickness is achieved (up to the Y-Y line in FIG. 8). (56) has a gap (5) along the wall (53a).
5) remains. This cavity (55) has a wall surface (53a
), and tends to increase with the depth of the groove (53), that is, with the film thickness of the lower magnetic III (54).

In this way, if the void (55) is exposed on the ground surface (56), it will adversely affect the patterning of the insulating film, coil conductor, upper magnetic film, etc. formed on the ground surface (56) of the iron, and the coil This causes a short circuit in the conductor or variations in track width, leading to a decrease in yield and further deterioration in in conversion characteristics and reliability.

The present invention has been proposed under such circumstances, and has no crosstalk from adjacent tracks, good patterning accuracy of the coil conductor and upper magnetic film, excellent electromagnetic conversion characteristics and reliability, and a good yield. An object of the present invention is to provide a method for manufacturing a thin S magnetic head.

[Means for solving the problem] In order to achieve the above-mentioned object, the present invention forms a track width regulating groove having a width equal to the trunk width on a substrate by reactive ion etching, and furthermore, the track width regulating groove has a width equal to the trunk width. The inner side of the width regulating groove is etched to a predetermined groove depth by taper etching so that the wall surface becomes an inclined surface. After that, a lower magnetic film is deposited and the surface is ground. After that, the coil conductor and upper magnetic film are photo-etched. It is characterized by being formed by lithography technology.

[Effect]

In the present invention, the track width of the thin film magnetic head is regulated by trunk width regulating grooves formed on the substrate by reactive ion etching.

Further, since taper etching is performed on the inside of the trunk width regulating groove to form an inclined surface inclined at a predetermined angle, the shadow effect is eliminated when forming the lower magnetic film. Therefore, the void portion does not remain on the surface where the coil conductor, upper magnetic film, etc. are formed.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

To manufacture a thin film magnetic head by the manufacturing method of the present invention, first, as shown in FIG. Adhesion is formed using a forming technique.

The substrate (1) is made of Mn-Zn ferrite or Ni.
- A ferromagnetic oxide substrate such as Zn ferrite, a non-magnetic substrate such as ceramics, etc. can be used.

Further, the nonmagnetic film (2) is SiOx.

/l! A non-magnetic oxide material such as z(h, 'l''az○6, etc. is suitable. Here, the film thickness a of this non-magnetic film (2)
is preferably formed to be slightly thicker than a predetermined core thickness (thickness of the lower magnetic film) in consideration of the cutting allowance in the surface grinding process described later.

Next, as shown in FIG. 2, the nonmagnetic film (2) is etched to form track width regulating grooves (3).

The trunk width regulating groove (3) is located near the surface (4) corresponding to the surface facing the magnetic recording medium, and the wall surfaces (3a), (3)
a) It is formed so that the distance between them has a width Tw that is equal to the track width set as the head. In addition, if the groove depth b of the track width regulating groove (3) is too large, a gap will be created in a (3) during formation of the lower magnetic film due to the above-mentioned shadow effect; It is difficult to ensure the accuracy of grinding, so it is preferably set to about 2 to 3 μm.

Further, as the etching method, a reactive ion etching method is preferable, and the track width regulating groove (3) is formed so that the etching proceeds in a direction perpendicular to the upper surface (2a) of the non-magnetic film (2). . In other words, this groove (3
) to regulate the track width, so if the wall surface (3a) becomes an inclined surface that is inclined with respect to the upper surface (2a), this will cause variations in the trunk width, which is not preferable.

Next, as shown in FIG. 3, the track width regulating groove (
Taper etching is performed to a predetermined groove depth from a few micrometers inside 3) to form an inclined surface (5) inclined at a predetermined angle on the inside of 1(3).

The groove (6) formed by this inclined surface (5) and the wall surface (3a) becomes a groove for forming the lower magnetic film. Here, examples of the above-mentioned taper etching method include, for example, an ion etching method which has excellent anisotropy.

In addition, during the taper etching process described above, the substrate (1)
(To prevent over-etching, the substrate (1
) and the nonmagnetic film (2), for example, a Cr film having a high etching ratio (selectivity) to the nonmagnetic film (2) may be interposed.

Furthermore, as shown in FIG. 4, a non-magnetic film 11 including the groove (6) for forming the lower magnetic film is added. A lower magnetic film (7) is deposited over the entire surface of J (2).

The lower magnetic film (7) is made of a ferromagnetic amorphous alloy, a so-called ferromagnetic amorphous alloy, a Fe-Aβ-3i alloy, a Fe-Ni alloy, a Fe-Affi alloy, an Fe-3
Ferromagnetic metal materials such as i-based alloys and Fe-5i-Co-based alloys can be used, and the methods for forming the film include sputtering method, vacuum technique, ion blating method, cluster ion beam method, etc. Vacuum thin film formation technology represented by is adopted.

Here, the lower magnetic film forming groove (6) is formed such that its upper groove is perpendicular to the upper surface of the non-magnetic film (2) with a predetermined track width Tw; ) is composed of an inwardly inclined inclined surface (5), the lower magnetic film (
Even if 7) is applied, the shadow effect is eliminated and no voids are created in the groove (6).

Next, as shown in FIG. 5, surface grinding is performed until the non-magnetic film (2) is exposed to the lower magnetic film (7) and a desired core thickness is obtained. Note that the surface grinding ends at the groove depth of the track width regulating groove (3), that is, within the range of the wall surface (3a).

As a result, only the portion of the lower magnetic film (7) buried in the a(6) remains, and the lower magnetic film (7) regulated by the track width regulating groove (3) remains on the upper surface (8). ) is exposed. Furthermore, since the upper surface (8) is formed by surface grinding, it has excellent flatness and smoothness.

Next, as shown in FIG. 6, a coil conductor (11), an extraction electrode (13), and an upper magnetic film (
14) ktllFJ (10), (12) 'c through L Tlllfi next lamination L, (n form the circuit part.

This FIG. 6 is a sectional view taken along the line X--X in FIG. 5 after the electromagnetic transducer is formed.

As the magnetic circuit section, conventionally known structures and manufacturing methods can be adopted. In addition, in Fig. 6, four coils (11) are shown.
The head has a single-layer structure with a three-turn spiral winding structure.

In this way, the coil conductor (11) and the upper magnetic film (14)
Since these are formed on the flat upper surface (8), the accuracy of patterning them is greatly improved. Therefore, short circuits and the like of the coil conductor (11) are eliminated, and the yield is improved, and the reliability and electromagnetic conversion characteristics of the head are also significantly improved.

Also, the trunk width as a thin film magnetic head is the groove (6).
Since the magnetic field is precisely regulated by the lower magnetic film (7) filled in the magnetic field, good recording and reproducing characteristics can be obtained.

Furthermore, although not shown, the above-mentioned coil conductor (1
1), the upper magnetic tt9 (14), etc., and to ensure contact with the magnetic recording medium, a protective film made of a non-magnetic material is coated on the upper magnetic film (14). After forming the adhesive, a protective plate made of ceramic or the like is fused and bonded using an adhesive such as glass. Finally, in order to ensure sliding contact with the magnetic recording medium and obtain a predetermined depth length, cylindrical polishing was performed on the surface (4) corresponding to the surface facing the CR magnetic recording medium, completing the thin film magnetic head. do.

FIG. 7 shows an enlarged plan view of the magnetic recording medium contacting surface of the thin film magnetic head fabricated as described above. Note that FIG. 7 shows a thin film magnetic head in which a protective plate (17) is bonded with an adhesive (16).

As is clear from FIG. 7, the thin film head produced according to the present invention has a structure in which the track width Tw is regulated by the wall surface (3a) of the track width regulating groove (3). Therefore, when the present invention is applied to a multi-channel single-film magnetic head, the pseudo signals caused by the cocoon talk from adjacent tracks are improved, and the recording and reproducing characteristics are greatly improved. However, it goes without saying that the present invention is not limited to the above-described embodiments.

For example, if a non-magnetic substrate made of ceramics or the like is used as the substrate (1), the non-magnetic rf3. (2), and it is not necessary to form the lower magnetic film forming groove (6) in this nonmagnetic film (2). That is, after directly performing RIE on the non-magnetic substrate to form a track width regulating groove, taper etching is performed on the inside of the trunk width regulating groove to a predetermined depth to form a groove for forming a lower magnetic film, as in the previous embodiment. It may be formed. It goes without saying that even if the groove for forming the lower magnetic film is formed directly on the nonmagnetic substrate in this way, the same operation and effect as in the previous example can be obtained.

〔Effect of the invention〕

As is clear from the above description, according to the manufacturing method of the present invention, the track width standard i11 groove with a predetermined groove depth is formed on the substrate in R.
(After forming B, the groove for forming the lower magnetic film is formed by performing taper etching on the inside of this groove so that the perfect surface becomes an inclined surface. Therefore, the lower magnetic film is formed using thin film forming technology. Even if the film is coated, no voids will remain in the lower magnetic film forming groove.Therefore, the surfaces on which the coil conductor, upper magnetic film, etc. are formed will have excellent flatness and smoothness, and these coil conductors The patterning accuracy of the upper magnetic film is greatly improved, and the yield can be improved.Furthermore, a thin film magnetic head with excellent electromagnetic conversion characteristics and reliability can be provided.

Particularly, the present invention is suitable for a method of manufacturing a multi-channel 1M magnetic head, which improves pseudo signals due to crosstalk from adjacent trunks and provides good recording and reproducing characteristics.

[Brief explanation of the drawing]

1 to 6 show the manufacturing method of a thin film magnetic head according to the present invention according to its steps. FIG. 1 is a perspective view showing the nonmagnetic film forming step, and FIG. 2 is a perspective view showing the trunk width regulating groove forming step. 3 is a perspective view showing the taper etching process, FIG. 4 is a perspective view showing the lower magnetic film forming process,
FIG. 5 is a perspective view showing the surface grinding process, and FIG. 6 is a sectional view of a main part showing the coil conductor and upper magnetic film forming process. FIG. 7 is a front view showing a thin film magnetic head manufactured according to the present invention. FIG. 8 is a cross-sectional view of a main part showing a step of forming a lower magnetic film in a conventional manufacturing method. 1...Substrate 2...Nonmagnetic film 3...Track width regulating groove 3a...Wall surface 5...Slope surface 7... ... Lower magnetic film 11 ... Coil conductor 13 ... Extraction electrode 14 ... Upper magnetic film Fig. 1 Track number 4 candle 0 anti 41 Te 46 Process Fig. 2 No 1''-2) - La 1〉 Puene 11 Fig. 3 Fig. 4 Fig. 8 F 〒1
Goods! /' 1, Honzoku Shojiyo was a friend of one blade (7) To Kanai, the front view of the throat Figure 7.

Claims (1)

[Claims] A track width regulating groove having a width equal to the track width is formed on the substrate by reactive ion etching, and the inner side of the track width regulating groove is tapered etched so that the wall surface becomes an inclined surface. A method for manufacturing a thin-film magnetic head, comprising etching the groove to a predetermined depth, then depositing a lower magnetic film, surface grinding, and then forming a coil conductor and an upper magnetic film by photolithography.