JPS6247812A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To suppress the magnetic resistance, to obtain the desired magnetomotive force and to improve the head characteristics, by setting the sloping angle to the etching surface of a coil conductor provided to a lower layer at a level smaller than the sloping angle of the etching surface of a coil conductor formed on the first oil conductor. CONSTITUTION:The slopping angle theta1 of the etching surface of a lower coil conductor 3 is set smaller than the sloping angle theta2 of the etching surface of an upper coil conductor 6. Then a gentle level difference is formed to an upper magnetic main body 9 that is formed at a level difference part by securing alpha1<60 deg.. Thus the body 9 is fored with a sufficient section area of a magnetic path. Thus reduces the magnetic resistance and reduces the generation of magnetic saturation. In addition, the conductor 6 is formed flat with no recess nor projection. Thus the satisfactory magnetic characteristics can be obtained. Then an ion enters easily a shadow part produced by the level difference part of the conductor 3 when the conductor 6 is patterned since said level difference part has a gentle sloping angle. This reduces an unetched area. This eliminates the short circuit of the coil conductor and the desired magnetomotive force is produced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is based on PCM (Pulse Code Mod
ulation) Thin +1' used in recording and reproducing devices, etc.
2 magnetic heads, and particularly relates to improvements in coil conductors in spiral multilayer thin film magnetic heads.

[Summary of the invention]

The present invention provides a thin film magnetic head formed by laminating a plurality of spiral coil conductors, in which the angle of inclination of the etched surface of the coil conductor disposed in the lower layer is the same as the etching angle of the coil conductor formed on the coil conductor. By configuring the head so that the angle of inclination is smaller than the angle of inclination of the surface, magnetic resistance can be suppressed and a desired magnetomotive force can be obtained, thereby improving head characteristics.

[Conventional technology]

In general, in thin-film magnetic heads, the coil conductor, upper magnetic material, insulating layer, etc. that make up the head are formed using vacuum thin-film forming techniques such as sputtering, which makes it possible to mass-produce heads with uniform characteristics. In addition, since patterning is performed using photolithography technology, miniaturization of narrow trunks, narrow gaps, etc. is easy.

Therefore, in this type of thin film magnetic head, the head magnetic field involved in recording becomes steep, enabling high-density recording, high-resolution recording, and further miniaturization.

Therefore, with the progress of vacuum thin film forming technology, so-called spiral type thin film magnetic heads, in which a coil conductor is spirally wound, have been put into practical use.

The spiral type WJ film magnetic head described above has advantages such as being able to form a large number of windings with a single layer of coil conductor and simplifying the manufacturing process.

Furthermore, in order to obtain higher magnetomotive force, so-called spiral multilayer thin film magnetic heads, in which a plurality of the spiral coil conductors described above are laminated with an insulating layer interposed therebetween, have been widely put into practical use.

As shown in FIG. 7, the spiral multilayer thin film magnetic head has a first insulating layer (51) made of 5i02 or the like on a lower magnetic body (50) made of a soft magnetic material such as Mn-Zn ferrite. ), a lower coil conductor (52) is formed in a spiral shape with several turns (2 turns), and an upper coil conductor (54) is formed on this lower coil conductor (52) via a second insulating layer (53). Similarly, several turns (1 turn)
The lower coil conductor (52) and the upper coil conductor (54) are electrically connected through a contact window (not shown). Furthermore, a gap film (58) is formed near the front gap, and a coil conductor (52) is formed between the magnetic poles.

(54) An upper magnetic body (57) made of a soft magnetic material such as sendust is formed to cover the bank gap portion and regulate the trunk width. Therefore, by supplying a driving current to the coil conductors (52) and (54), a closed magnetic path is formed between the lower magnetic body 50) and the upper magnetic body (57), and recording/reproduction is performed. It is composed of

Here, usually each of the above-mentioned coil conductors (52), (54
), a metal conductor such as Cu or Ae is deposited over the entire surface of the lower magnetic body (50), a resist pattern of a predetermined shape is formed on the metal conductor, and then etched by a method such as ion etching. It is formed by patterning.

[Problem that the invention seeks to solve]

However, according to the inventor's experiments, simply performing ion etching using the above-mentioned resist pattern does not
It has been found that the etched surface of the lower coil conductor (52) is scraped off substantially vertically, and its inclination angle α becomes large, resulting in a steep stepped portion. For this reason, the upper magnetic body (57) formed in this stepped portion is largely bent, and in particular is formed at an almost angle α on the etched surface, so that the film j7 is formed thinner than in the flat portion.

Therefore, in the stepped portion, the magnetic path cross-sectional area becomes small and the magnetic resistance becomes large. In some cases, magnetic flux saturation may occur, and if the upper coil conductor (54) is formed on the lower coil conductor (52) having such a steep step, unevenness is likely to occur in the upper coil conductor (54). , it becomes difficult to form a flat upper magnetic body (57). This results in deterioration of magnetic properties.

Furthermore, when patterning the four upper coils (54), if ion etching is attempted in the same manner as the lower coil conductor (52), the lower coil conductor (52)
Since the stepped portion is steep, it is difficult for ions to enter the shadowed portion by the stepped portion, and the metal conductor remains along the stepped portion. Therefore, there is a problem in that the upper coil conductor (54) is short-circuited and a predetermined magnetomotive force cannot be obtained.

Therefore, a method can be considered to completely remove the metal conductor at the stepped portion by increasing the etching time, but with this method, the second insulating layer (53) is also etched (so-called over-etching), which may cause dielectric breakdown. There is. In some cases, even the lower coil conductor (52) is etched, which increases the resistance of the coil conductor and deteriorates the S/N ratio.

Therefore, the present invention has been proposed in view of the above-mentioned circumstances, and has a low magnetic resistance and a desired magnetomotive force.
Fi with excellent head characteristics! The purpose is to provide a nod to membrane magnetism.

(Means for Solving the Problems) In order to achieve this object, the thin film magnetic head of the present invention has a plurality of layers of coil conductors and an upper magnetic body laminated on a lower magnetic body with an insulating layer interposed therebetween. In the thin film magnetic head, when the inclination angle of the etched surface of the coil conductor disposed in the lower layer is 01, and the inclination angle of the etched surface of the coil conductor formed on the coil conductor is 02,
It is characterized by being configured so that θ1<θ2.

[Effect]

In this way, by controlling the inclination angle of the etched surface of the coil conductor, the level difference caused by this coil conductor is alleviated, and the magnetic path cross-sectional area of the upper magnetic material at this level difference part can be secured, and magnetic resistance can be suppressed. . Furthermore, when etching the upper coil conductor, the etching is performed at a larger angle than the etching surface of the lower coil conductor, so ions are more likely to enter the shadowed area by the stepped portion, and no etching remains.

〔Example〕

An embodiment of a thin film magnetic head to which the present invention is applied will be described below with reference to the drawings.

In the thin film magnetic head of the present invention, as shown in FIGS. 1(A) and 1(B), SiO2 is formed on the lower magnetic body (1) except for the front gap and back gap.
A first insulating layer (2) made of, etc. is formed, and a gap film (8) made of Ta205 or the like is formed on the front gap portion so as to have a predetermined gap length.

The lower magnetic body (1) is a ferromagnetic oxide substrate such as Mn-Zn ferrite or Ni-Zn ferrite, or a Fe-Ni alloy (Fe-Ni alloy) on a nonmagnetic substrate such as ceramic.
Par? C) A), a composite substrate in which a ferromagnetic metal material such as Fe-Al-3i alloy is laminated, or a composite substrate in which a ferromagnetic metal material such as Permalloy or Sendust is laminated on the ferromagnetic oxide substrate, etc. Available for use.

Further, on the first insulating layer (2), a lower coil conductor (3) made of a metal conductor such as Cu or A1 is formed in a spiral shape (two turns in this embodiment) at a predetermined interval.

Further, a second insulating layer (4) is formed to cover the lower coil conductor (3), and this second insulating layer (4) l
has the same winding direction as the lower coil conductor (3) and is electrically connected to the lower coil conductor (3) through the contact window (5) of the second insulating layer (4). A spiral (one turn in this embodiment) upper coil conductor (6) is formed. Of course, the coil conductor of this embodiment has a spiral two-layer, three-turn winding structure.

Here, in the present invention, the lower coil conductor (3)
The inclination angle θ1 of the etched surface of the upper coil conductor (6
) is formed to be smaller than the inclination angle θ2 of the etched surface. Moreover, the above-mentioned θ1 is formed to be smaller than 600.

Furthermore, a third insulating layer (7) is formed on the upper coil conductor (6) in order to insulate it from an upper magnetic body (9), which will be described later. Further, the third insulating layer (7
), an upper magnetic body (9) made of a ferromagnetic metal material such as sendust or permalloy is formed to cover the gear film (8) and the pack gap portion so as to have a predetermined track width. Therefore, the above coil conductor (3), (
6) by supplying a drive current to the lower magnetic body (1
) and the upper magnetic body (9) form a closed magnetic path,
It is configured to perform recording and playback.

Furthermore, although not shown, a 2N film such as 5i02 is formed to cover the upper magnetic body (9), and after annealing, the 3! The film is flattened by melting and filling an adhesive such as glass onto the film, and a protective plate made of a non-magnetic material such as ceramic is fused and bonded onto the adhesive to prevent wear of the surface facing the magnetic recording medium. has been done.

In the thin film magnetic head constructed in this way, the etched surfaces of each coil conductor (3) and (6) are constructed so that the inclination angle is θ, <θ2, and by setting θ1 to 60°, Upper magnetic body (9) formed at the step part
is formed gently by reducing the level difference. That is, the upper magnetic body (9) of this stepped portion is formed with a sufficient magnetic path cross-sectional area, so that the magnetic unidirectional resistance can be reduced and magnetic flux saturation is less likely to occur.

Further, since the upper coil conductor (6) is formed flat without any unevenness, good magnetic properties can be obtained. Furthermore, since the stepped portion of the lower coil conductor (3) is formed with a gentle inclination angle, when patterning the upper coil conductor (6), ions are more likely to enter the shadowed portion of the stepped portion, and the etching residue is removed. disappears. Therefore, the coil conductor is not short-circuited, and the desired magnetomotive force can be obtained.

Below, thin 11 of the present invention! In order to make the structure of the magnetic head more clear, the manufacturing method thereof, particularly the method of forming the coil conductor, will be described in detail.

First, as shown in FIG. 2, a metal conductor (13) such as Cu is deposited on the lower magnetic body (11) via a second insulating layer (I2) using a vacuum thin film forming technique such as sputtering.

Next, ``Biped metal m body (13) J two and Regis 1-(
14) Apply.

”The coating thickness of 1-(14) is = L metal 13
This is important for improving the etching accuracy (ion etching in this embodiment) of the body 13). That is, if the thickness of the metal conductor (13) is the coating thickness B of the Al resist, the etching rate of the metal conductor (13) is Ea, and the etching rate Eb of the resist, then the coating thickness B of the resist is as follows: B = x 1.2+8 TE a/
It is preferable to apply the coating so that E b is obtained. Here, ΔT is the resist coating thickness to compensate for variations due to sputtering equipment and etching equipment.

Next, as shown in FIG. 3, the resist (14) is subjected to techniques such as prebeta, mask alignment, exposure, and development to form a resist pattern (14a). At this time, the contact pressure and exposure amount are controlled so that the inclination angle β of the resist pattern (14a) is approximately 70°. Here, it is preferable to form the above β to be as small as possible; if β is too large, the angle of inclination of the etched surface of the lower coil conductor (12a) will become large.

Subsequently, as shown in FIG. 4, ion etching is performed while rotating the lower magnetic body (11) to form a lower coil conductor (14a). The above ion etching was performed with the ion incidence angle (regis) (14a) angle relative to the normal direction of the top surface) set to 30''.As a result, the lower coil conductor (], 2a) has an inclination angle of θ1 is about 6
The conductor shape had a gentle slope of 0'.

Next, upon completion of the etching described above, the resist (14a) which has become unnecessary is removed.

Furthermore, as shown in the fifth circle, the lower coil conductor (1
3a) After depositing a second insulating layer (15) on the second insulating layer (15), a metal conductor (16) is formed by sputtering so as to cover the second insulating layer (15).
Since the inclination angle θ1 in a) has a gentle shape of approximately 60°, the metal conductor (16) laminated on the lower coil conductor (1, 3a) follows the shape of the lower coil 4 (13a). This eliminates the formation of irregularities on the edges of the metal conductor (16).

Next, as shown in FIG. 6, the lower coil conductor (
Similar to etching 14a), the upper coil conductor (16a
) to form. In etching the upper coil conductor (16a), first, most of the metal conductor (16) was removed by setting the ion incident angle to 30'', and then etching was performed by changing the incident angle to 10'.

In this way, by performing etching by changing the incident angle of ions, the ions can more easily enter the stepped portion, and the metal conductor (16) at the stepped portion can be completely etched in a short time (minimum Oher etching). It can be removed with Therefore, short-circuiting, disconnection of the coil conductor, dielectric breakdown, etc. are less likely to occur, and the desired magnetomotive force can be obtained.

In addition, although not shown in the figure, there is a registration that is no longer needed) (
17) was removed and a third insulating layer was formed to cover the upper coil conductor (16a), and then each insulating layer on the front gap portion and the hack gap portion was removed, and 20g of Ta was applied to the front gap portion. A gap film consisting of the following is formed. Further, an upper magnetic body made of a ferromagnetic metal material such as sendust is formed so as to cover the gap film and the coil conductor wound between the magnetic poles. Subsequently, the surface facing the magnetic recording medium is cut and polished to complete the thin film magnetic head shown in FIGS. 1(A) and 1(B).

Therefore, the upper coil conductor (6) formed between the magnetic poles
are formed to fill the gap between the lower coil conductors (3), so these coil conductors (3) and (6
) is formed to have a substantially flat surface, and as a result, the upper magnetic body (
9) is formed substantially flat. In addition, the lower coil conductor (3
) is formed so that the inclination angle θ1 is 60°, so the upper magnetic body (9) at the stepped portion is sputtered thicker than in the past. Therefore, the cross-sectional area of the magnetic path at the stepped portion is larger than that of the conventional one, making it possible to suppress magnetic resistance, making it difficult for magnetic flux saturation to occur, and obtaining good magnetic properties. Although a thin II# magnetic head in which two layers of conductors are laminated with an insulating layer interposed therebetween has been described, the present invention is also applicable to a spiral multilayer thin film magnetic head in which the above coil conductors are laminated on three chamfers. That is, the angle of inclination of the etched surface of the coil conductor disposed in the lower layer is smaller than the angle of inclination of the etched surface of the coil conductor formed on this coil conductor,
Preferably, the taper angle of the lower layer coil conductor is 60.
``If the configuration is as follows, the same actions and effects as in this embodiment can be obtained.

〔Effect of the invention〕

As is clear from the above description, in the thin film magnetic head of the present invention, the inclination angle of the etched surface of the lower coil conductor is
Since the angle of inclination of the etched surface of the upper coil conductor is smaller than that of the upper coil conductor, the upper magnetic body formed on these coil conductors is formed with a gentle step difference, and magnetic resistance can be suppressed. Furthermore, when etching and etching the upper coil conductor, ions are more likely to enter the stepped portion, and bettering can be performed without etching residue or over-etching, so that a desired magnetomotive force can be obtained. Therefore, according to the present invention, a thin film magnetic head having good head characteristics can be provided.

[Brief explanation of the drawing]

1(A) and 1(B) show an embodiment of a thin film magnetic head according to the present invention, FIG. 1(A> is a plan view, and FIG. (A) is a cross-sectional view taken along line a-a. FIGS. 2 to 6 are enlarged cross-sectional views of main parts showing the manufacturing method of the coil conductor constituting the thin-film magnetic head of the present invention according to the process order; The figure shows the resist coating process for forming the lower coil conductor, FIG. 3 shows the resist developing process, FIG. Figure 6 shows the etching process. Figure 7 is an enlarged cross-sectional view of the main parts of a conventional thin film magnetic head. 1...Lower magnetic body 3...Lower coil conductor 6...・Top coil conductor 9...Top magnetic body

Claims (1)

[Claims] In a thin film magnetic head in which a plurality of layers of coil conductors and an upper magnetic material are laminated on a lower magnetic material with an insulating layer interposed therebetween, the inclination angle of the etched surface of the coil conductor disposed in the lower layer A thin film magnetic head characterized in that it is configured such that θ_1<θ_2, where θ_1 is an inclination angle of an etched surface of a coil conductor formed on the coil conductor.