JPS61178711A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To cause a structure which can easily make a magnetic core into a multilayer and to form a thin film magnetic head with high recording efficiency by constituting a thin film core in such away that a thin film magnetic core film and a thin film conductive coil are embedded in the prescribed groove part (removal part) drilled on a nonmagnetic insulating film. CONSTITUTION:A nonmagnetic electric insulating material 3 made of glass etc., lies on the groove part 2 of the magnetic substrate 1, and a coil conductor 4 is embedded on the surface of said material 3. On the entire surface of the substrate 1 a nonmagnetic electric insulating film 5 is piled up, and some part of said film 5 (part where the coil conductor 4 is embedded) is removed as a magnetic core part 6 and a through hole part 7. Then the latter 7 is masked to pile up a nonmagnetic electrical insulating film 8, and thereon a metallic magnetic film 9 is accumulated (namely, it is embedded as the magnetic core part 6 in the removed part) and ground up to a line A-A'. The nonmagnetic electric insulating film 5 can remove a part becoming the magnetic core part 6 by the appropriate taper angle.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a thin film magnetic head, and in particular, a magnetic circuit is formed by a magnetic substrate and a thin film magnetic core (magnetic thin film core), and a thin film conductor is attached to the magnetic thin film core. The present invention relates to a magnetic thin film magnetic head formed by winding a coil, and particularly to a multi-track magnetic head used for digital magnetic recording and reproduction.

(Conventional technology and its problems) In recent years, the density of digital magnetic recording and reproducing systems has increased!
! In line with this trend, thin-film magnetic heads using conventional IC process technologies, especially WI film fabrication technologies such as evaporation, sputtering, and CVO (Chemical Vapor Deposition), and microfabrication technologies such as dry etching, have been attracting attention and are rapidly gaining attention. It has been put into practical use in some areas.

This i'ig! Compared to conventional monolithic magnetic heads, the magnetic head can have narrower tracks and more tracks, has steep recording leakage flux, and has excellent short wavelength recording characteristics, making it suitable for use in ing. Furthermore, in terms of productivity, since a wafer process is used, a homogeneous magnetic head with excellent mass productivity can be provided. For these reasons, for example, multi-element magnetic heads are used as magnetic heads for audio PCM recording.
Magnetic induction type II for recording! A film magnetic head is used, and a magnetoresistive type f111! is used for reproduction. A magnetic head is used.

Conventional thin-film recording magnetic heads are made by patterning one or two layers of metal conductor into a spiral pattern on a flat surface, and due to track pitch and processing limitations, it is not possible to increase the number of windings. , recording current is large, heat dissipation is slow, coupling with IC circuit is difficult, and at the same time induced electromotive force is small, so the reproducing head becomes a thin Illfa head using a different principle and a completely different process. was.

On the other hand, a thin film magnetic head with a winding structure that can increase the number of windings is one in which 1111 conductor coils are patterned on the upper and lower parts of a 1ilW41i1 core through electrical insulation films, and this structure (hereinafter referred to as (referred to as a three-dimensional helical type), a planar spiral type IF! Compared to the wire structure, the number of m-wires is not limited by the track pitch, so it is possible to have several tens to several thousand turns, compared to about 10 turns or less in the flat spiral type. Since it is of the magnetic induction type and can record with a minute recording current, and has a large reproduction output, a recording/reproduction head can be made using the same process.

However, the conventional SMM head as described above has the following problems.

(2) Since the cross-sectional area of the fil film magnetic core is small, sufficient magnetic flux cannot be applied to the recording gap by the thin film conductor coil, and therefore the recording level is small.

(2) Similarly, since the magnetic resistance of the winding portion of the # film magnetic core is high, sufficient reproduction output cannot be obtained.

■Etching reproducibility of magnetic film is low and yield is low.

■Wiring breakage occurs at stepped wiring sections, resulting in low yield.

Therefore, the present invention solves the above-mentioned problems of the conventional technology, and the cross-sectional area of the winding portion of the thin film magnetic core is increased, and the yield is high. The purpose is to provide a magnetic head.

(Means and effects for solving the problems) In order to achieve the above object, the present invention forms a 1 m film magnetic core by using a non-magnetic film instead of etching the magnetic core film as in the conventional method. By embedding a thin film magnetic core film and a thin film conductor coil in a predetermined groove (removed part) formed in an insulating film, the film deposition and processing surface can always be flat with small steps, and therefore the multilayer magnetic core can be The present invention provides a thin-film magnetic head that has a structure that is easy to convert, thereby increasing the cross-sectional area of the winding portion of the magnetic core and providing high recording efficiency.

(Example) Regarding the first example of the film magnetic head according to the present invention,
This will be explained below along with the drawings.

1 to 8 are diagrams for explaining a first embodiment of a thin film magnetic head according to the present invention.

In Figures 1 and 2, magnetic! ! A non-magnetic electrically insulating material 3 such as glass is provided in the groove 2 of the plate 1, and a coil conductor 4 is embedded in the surface thereof.

Furthermore, the entire surface of this substrate 1 is coated with non-magnetic electrical insulation such as Si 02.3i N! s5 is accumulated by a forming method such as M deposition, sputtering, or CVO (chemical vapor deposition), and then a part of the nonmagnetic electrical insulating film 5 (the part where the coil conductor 4 is buried) is deposited. ,
As the magnetic core part 6 and through hole part 7, photo
It is removed using lithography, dry etching technology, etc.

Next, as shown in FIG. 3, the through hole portion 7 shown in FIG. 2 is masked, and Aj 203. Non-magnetic type stun 1i11 such as Si 02
A metal magnetic film 9 made of permalloy or the like is then buried in the portion that was removed as the magnetic core portion 6, and then, as shown in FIG.
Polish to line A'. FIG. 4 is a perspective view showing the surface of the substrate finally polished as explained above, in which 7a is the polished surface of the through-hole portion 7, and 9a is the polished surface of the metal magnetic film 9. It is.

5 is a sectional view taken along line B-8' in FIG. 4, and FIG. 6 is a sectional view taken along line cc' in FIG. 4. This figure shows the structure of the magnetic head. The figure shows the shape of the vicinity of the recording gap when viewed from the magnetic tape sliding surface.

As shown in FIGS. 5 and 6, the nonmagnetic electrical insulating film 5 made of s+02 or the like has an anisotropic shape in the portion that will become the magnetic core portion 6, as is clear from the cross-sectional shape of the magnetic core portion 6. The magnetic core 6 can be removed at an appropriate Taber angle (in the figure, the magnetic core 6 has an inverted trapezoidal shape) by means such as plasma etching.

In addition, as shown in Figure 4, the manufacturing process up to this point yields a flat substrate with no steps on the surface, so the same manufacturing process can be repeated on it, and in that case, Figure 6 corresponds to A cross-sectional view is shown in FIG.

Figure 7 shows the same manufacturing process as above repeated three times.
This figure shows the case where the magnetic core portions 6.6', 6'' of the layers are formed, and in this case, the non-magnetic electrical insulation 15.5',
It is possible to remove the portions of the 5" magnetic core parts 6°5/, 5// based on the method of creating a Taber angle using anisotropic plasma etching as described above, which reduces mold costs. be.

In FIG. 7, the etched bottom width W1 of the magnetic core portion 6 is always smaller than the etched top width W2, so that the layer of metal magnetic film such as permalloy that becomes the magnetic core portion 6 is and 11 serve as stoppers for the non-magnetic electrical insulating films 5' and 5'', and etching is therefore completely completed on these surfaces.Therefore, no damage to the wafer due to over-etching occurs.

Figure 8 shows a wafer in which coil parts and lead parts (outgoing wires) are formed on a substrate having a three-layer magnetic core part (14i core theory) 6.6', 6'' as shown in Fig. 7. FIG. 2 is a perspective view showing a part of the coil conductor (upper coil conductor) 13 and the lead portion 14 on the non-magnetic electrical insulating film 5 (5', 5'') via the insulating layer 12. sl!
It is formed by depositing and further buttering. Then, the coil conductor (lower coil conductor) is connected by the through hole part 7.
4 (shown in FIGS. 1 to 3), the coil conductor (upper coil conductor) 13, and the lead portion 14 are electrically connected (conducted).

Next, a second embodiment of the present invention will be described.

FIGS. 9 and 10 are diagrams for explaining a second embodiment of the thin film magnetic head according to the present invention. Note that the same parts as those in the previous figure are given the same reference numerals, and the explanation thereof will be omitted.

In FIG. 9, the magnetic material constituting the recording gap is a metal magnetic film having a high saturation magnetic flux density. That is, in the case of this embodiment, the 111th magnetic core section is separated into the recording gap section 61 and the coil winding section 62, and before depositing the second layer of the magnetic core section 63, the insulating layer 15 serving as the gap is separated. Form it. Then, in the same manner as above, the second layer 63 and the third layer 6'' are formed, and the coil conductor (
An upper coil conductor) 13 and a lead portion (not shown) are formed.

With this configuration, as shown in FIG. 10, which shows a cross-sectional view taken along the line D-D' in FIG. A thin film magnetic head is obtained.

FIGS. 11 and 12 are diagrams for explaining a third embodiment of the present invention. 43. The same parts as those in the previous figure are given the same reference numerals, and the explanation thereof will be omitted.

In this embodiment, when removing the second layer and the 311th non-magnetic electrical insulator 1151.52, the removal pattern of the portion that will become the magnetic core portion is changed from that of the above embodiment, as shown in FIG. Instead, the cross-sectional area of the magnetic core on the tape sliding surface of the magnetic head (cross section taken along line EE' in FIG. 11) is reduced, thereby improving recording efficiency.

That is, only the magnetic core part 61 of the first layer and the magnetic core part 6' of the second IN are made to be the tape sliding surface (line E-E'), and the third! ! The formation position of the third layer magnetic core portion 6'' is changed so that the third layer magnetic core portion 6'' does not become the tape sliding surface. In addition, in FIG. 11, a nonmagnetic film 16 is added in order to define the life dimension.

Moreover, FIG. 12 is a sectional view taken along the line EE' in FIG. 11.

Note that the above explanation is based on the case where the metal magnetic film is J! Although the structure is such that it also serves as a part of the wire cocoil, other manufacturing processes may be used in view of magnetic and coil resistance values, and these do not define the content of the present invention.

As described above, according to the embodiment of the present invention, since the cross-sectional area of the mva portion of the sm magnetic core is increased, a head with good recording and reproducing efficiency can be obtained.

■Processes such as photolithography and etching to remove the magnetic core part and through-hole part of the non-magnetic electrical insulating film are performed on a flat surface (substrate surface) with small steps, so disconnections at steps may occur. There are no such problems.

■To determine the shape of the magnetic material, we do not etch the magnetic film, but perform precise plasma etching of the insulator such as 5i02, so there may be problems such as underlayer spots or abnormal etching that occur when etching the magnetic material. This eliminates problems such as pattern disturbances and defects, and improves yield.

■The multilayer structure of the thin-film magnetic core makes it possible to narrow the tip of the recording gap, resulting in good recording efficiency.

■Since the recording gap is made of gold aS, recording efficiency is good.

(Effects of the Invention) As described above, the thin film magnetic head of the present invention has the following features.

■Since the cross-sectional area of the winding portion of the thin-film magnetic core is large, recording and reproducing efficiency is good.

■By making the fi11 magnetic core a multilayer structure,
Since the leading edge of the recording gap can be narrowed down, recording efficiency is improved.

[Brief explanation of the drawing]

1 to 8 are diagrams for explaining the first embodiment of the l-film magnetic head according to the present invention, and FIGS. 1 and 3 are side sectional views of the main parts of the embodiment of jll. , Figures 2 and 4 are perspective views of the first embodiment, Figure @5 is a cross-sectional view taken along line B-8' in Figure 4, and Figure 6 is a cross-sectional view taken along line c-c' in Figure 4. 7 is a sectional view showing the state of the manufacturing process after the cross section corresponding to FIG. 6, and FIG. 8 is a perspective view showing the final state of the first embodiment. 9 and 10 are diagrams for explaining a second embodiment of the 5inW1 air head according to the present invention, FIG. 9 is a side sectional view of the main part of the second embodiment, and FIG. is D- in Figure 9.
It is a sectional view taken along D' line. 11 and 12 are diagrams for explaining the third embodiment of the thin film magnetic head according to the present invention, and FIG.
FIG. 12 is a side sectional view of a main part of the embodiment I3, and FIG. 12 is a sectional view taken along line EE' in FIG. DESCRIPTION OF SYMBOLS 1...Magnetic board, 2...Groove part, 3...Nonmagnetic electric insulating material, 4...Coil conductor, 5
, 5', 5", 51.52...Nonmagnetic electrical insulating film, 6, 6', 6", 61.62.63...
- Magnetic core part, 7... Through hole part, 7a... Polished surface of through hole part 7, 8... Nonmagnetic electrical insulating film, 9... Metal magnetic film, 9a... Polished surface of metal magnetic film 9, 10, 11... Polished II surface, 12... Insulating layer, 13.
...Coil conductor, 14...Lead part, 15.16...
・Insulating layer. p T q 6' 10 傑7 12 15

Claims (4)

[Claims] (1) In a thin film magnetic head in which a magnetic circuit is formed by a magnetic substrate and a thin film magnetic core, and a thin film conductor is wound around the thin film magnetic core, a predetermined removed portion of a nonmagnetic insulating film provided on the magnetic substrate is provided. A thin film magnetic head comprising a thin film magnetic core and a thin film conductor coil embedded therein. (2) The thin film magnetic core is formed in at least two layers, of which one layer on the magnetic substrate side is separated into a head tip portion and a coil winding portion. The thin film magnetic head described in Section 1. (3) The thin film magnetic core is formed in at least two layers, and the number of layers on the magnetic tape sliding surface of the thin film magnetic core is smaller than the number of layers on the coil winding portion. A thin film magnetic head according to claim 1. (4) The thin-film magnetic head according to claim 1, wherein each of the thin-film magnetic cores has an inverted trapezoidal cross-sectional shape on the magnetic tape sliding surface.