JPS6292219A - Magneto-resistance effect type thin film magnetic head - Google Patents

Abstract

PURPOSE:To obtain a head having a high reproducing efficiency by providing a recess to a magnetic tape slide part of a magnetic base end in providing a thin film magnetic head thereto, insulating the recess from the base by an electric insulation film, providing a gap formed by conductors surrounded by a magnetic yoke in the recess and fitting the head onto the gap. CONSTITUTION:The recess 13 is provided to the slide part 12 slided to the magnetic tape at the end of the magnetic base 11 while being placed at the surface layer of the base 11 and a bias magnetic flux provision conductor 17 whose top face is mated with the surface of the base 11 is formed to the bottom center via an electric insulation film 14. Then the side face of the conductor 17, the bottom and rear side wall of the recess are covered by insulation films 14a, 14b, a front magnetic yoke 15 and a rear magnetic yoke 16 are embedded to both sides of the conductor 17 to press the end 15a of the yoke 15 into contact onto the tape. Then an insulation film 20 is coated on the entire face, placed on the gap 19 formed by the conductor 17, a head 18 is bonded to form a magnetic closed circuit 21 in the recess 13 and in the base 11 thereunder. Plural magnetic heads 18 as above are provided in parallel with the base 11.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a magnetic head using a magnetoresistive element made of a ferromagnetic thin film, and in particular to a magnetic yoke-type head that uses a magnetic yoke to guide signal magnetic flux to a magnetoresistive element. magnetoresistive element f
lu [Relating to 6 air heads.

(Prior Art) Conventionally, a thin film magnetic head (hereinafter referred to as an MR thin film head) using a magnetoresistive effect element (hereinafter referred to as an MR element) made of a strong vArt thin film (hereinafter referred to as an MR thin film head) uses a coil Compared to an electric RA induction barrel type thin film magnetic head that uses
It has high playback sensitivity when running a magnetic tape at low speed, and it is easy to narrow the track, so it is used as a multi-track magnetic head for high-density magnetic recording.

Conventionally, this type of MRIif+ film head uses a so-called shield type in which the MR element is directly exposed on the sacral surface of the magnetic tape layer, a so-called non-shield type, and a magnetic yoke that uses a magnetic yoke to transfer the magnetic flux to the internal MR head. There is a so-called yoke type that leads to the element.

FIG. 6 shows a cross-sectional view of a conventional yoke-type MRID film head. In the figure, 1 is a conventional M fl thin-print head, and 2 is a Mn-Zn ferrite or Ni-
A magnetic substrate made of Zn ferrite etc. makes magnetic tape l!
! ? It has a wall surface 2a that is the initial surface and a plane 2b that is substantially perpendicular to the wall surface 2a.

3 is a magnetic gap made of a magnetically and electrically insulating film such as 5i02, which is provided on the plane 2b of the magnetic substrate 2 by known thin film forming means.

4 is a conductor 4 which applies a bias magnetic field to the MR element in 1 below (in this book, it is made of metal Δl, Al-Cu, MO'8).

5 is Al2O3 or SiO provided to cover the conductor 4.
This is an electrical insulating film consisting of 2.

6 is a thin film color 13 such as N1-Fe, Ni-Co, etc.
The IR element is provided on the conductor 4 with an electrical insulating film 5 interposed therebetween.

Reference numeral 7 denotes an electrical insulating film made of Al2O3 or SiO2 for insulating the IvlR element 6.

8 is a front magnetic yoke provided on the conductor 4 through the electrical insulating films 3, 5.7, one end 8a of which faces the magnetic substrate 2 through the magnetic gap 3a, and is connected to the tape slider along with the wall surface 2a. It forms part 8b of the moving surface, and has a core width equivalent to the width of a recording track (not shown) in a direction substantially perpendicular to the plane of the paper.

Similar to the front magnetic yoke 8, 9 is a rear magnetic yoke that is installed on the conductor 4 via electrical insulation 13, 5°7, and its one end 9a is 114 and the other end 8C of the magnetic yoke 8 is MR wood. The other end 9b is connected to the flat surface 2b of the magnetic substrate 2. From the above configuration, the front magnetic yoke 8. Senry Gitotsubu SG, rear magnetic yoke 9.
One 88 magnetic closed circuit consisting of the magnetic substrate 1 and the magnetic gap 3a can be constructed, and the conductor 4 and the MR element 6 are arranged in this magnetic closed circuit S.

As shown in the upper part, the front magnetic yoke 8 and the rear magnetic yoke are provided on the insulating film 14 and 16 that forms the step.
These magnetic yokes 8.9 have steps (
j+, d2, etc. are occurring.

In the above configuration, the signal magnetic flux from the magnetic tape (not shown) running on the tape layer planes 2a and 3b starts or ends at the wall surface 2a and a portion 8b of the tape sliding surface of the front magnetic yoke 8, respectively. It flows through the spiracle circuit S,
At this time, a part of the single fertile flux passing through the Senry Gap SG becomes leakage magnetic flux and flows through the MR element, so the change in the resistance value of the MR completion due to the change in magnetic flux is caused by the output voltage through a known electric circuit. This change is taken out to the outside as a playback output.

At this time, a current is applied to the conductor 4 to provide a bias electric field that maximizes the rate of change in resistance of the MR element 6.

The problems of the conventional yoke type MR thin film head mentioned above are as follows: (1) When forming the pattern of the front and rear magnetic yokes 8.9 on the insulating film 7 by F1-1 tweezing,
Since the insulating film 7 is provided on the conductor 1, it has an uneven portion J3, and the patterns of the front and rear magnetic yokes 8.9 provided thereon result in step differences d, d2. , the above pattern cannot be formed with good viscosity.

(2) The magnetic properties, particularly the LA permeability μ, tend to deteriorate in the steps d1 and d2 of the rear magnetic yoke 8.9, resulting in a reduction in the reproduction efficiency of the magnetic head.

(3) When a flat protective substrate (not shown) is provided on the surfaces of the front and rear magnetic yokes 8.9 with adhesive to form a highly wear-resistant magnetic head, the difference caused by the step d1. The adhesive layer is easily worn out by the running of the tape.
In addition, dirt tends to adhere to the dents caused by wear, resulting in spacing loss and a reduction in reproduction output.

(Means for Solving the Problems) The present invention has been made to solve the above problems, and as a first invention, a wall surface serving as a magnetic Arp layer surface,
A magnetic substrate having a flat surface substantially perpendicular to the wall surface is provided, a cutout portion having a flat 111 portion is formed on the plane including the wall surface, a conductor for applying a bias magnetic field, and a magnetoresistive element. a magnetic field having a magnetic gap for giving magnetic flux to the magnetic substrate, respectively, through an electrically insulating film and an electrically insulating film that is to serve as a magnetic gap, so as to be at the same height as the plane of the magnetic substrate, and The above-mentioned sensor gap is configured and provided so as to be exposed on this plane, and the above-mentioned…low-temperature resistance effect! 11! A second invention of the present invention provides a thin film magnetic head of the magnetoresistive effect type, characterized in that an element is disposed near the exposed surface of the sensor gap. 2! A magnetic substrate having a wall surface serving as a moving surface and a plane approximately perpendicular to the wall surface is provided, and a notch portion having a flat portion is formed on the plane including the wall surface to apply a bias magnetic field. a first sensor having a conductor and a first sensor gap for applying magnetic flux to the magnetoresistive element;
and a magnetic yoke, respectively, through an electrical insulating film and an electrical insulating film to form a magnetic gap, so that they are at the same height as the plane of the magnetic substrate, and the sensor gap is exposed on this plane. Furthermore, a second magnetic yoke is installed to cover the first sensor gap, and the magnetoresistive element is placed near the second sensor gap. It is an object of the present invention to provide a magnetoresistive thin film magnetic head characterized by the following.

(Embodiment) FIG. 1 is a partially cutaway perspective view showing a first embodiment of the yoke type MR i'tD film head according to the present invention. The case where several Is are provided is shown. Figure 2 is I- of Figure 1.
FIG. 3 is a cross-sectional view of main parts taken along line I.

This will be explained below using FIGS. 1 and 2.

In the figure, numeral 10 is an MRR membrane head according to the present invention.

Reference numeral 11 denotes a magnetic substrate made of, for example, Mn-Zn ferrite, which includes a wall surface 11a serving as one movement surface 12 of the magnetic arp and a flat surface 1 formed substantially perpendicular to this wall surface 11a.
1b. 1 13 is provided on the plane 11b including the wall surface 11a or is missing, and is a rectangular flat surface I that is almost perpendicular to the wall surface 11a.
It has an n-plane 13a.

For example, 14 is S! The notch 1 is an insulating film made of 02 etc.
A conductor 17 and a notch 13, which will be described later, are provided on the inner wall of 3.
It plays the role of electrical insulation from the inner wall of the wall.

Reference numeral 15 denotes a front magnetic yoke made of a soft magnetic film such as Zendust, which has a gravity plane portion 15b having the same height as the tape 1 movement surface 15a formed together with the wall surface Ha and the plane 11b of the magnetic substrate 11. have.

Reference numeral 16 denotes a rear magnetic yoke, which is made of the same material II as the front magnetic yoke 15, and is installed inside the notch 13 so as to face it, and, like the front magnetic yoke 15, is made of the same material II and is located at the same height as the plane 11b. The rear plane part IGa is on the right.

The front and rear magnetic yokes 15.1G are provided inside the notch 13 with the electrical insulating films 14a to 14c interposed therebetween in the number of required magnetic heads.

Note that the electrical insulating film 14a has a magnetic gap (instinct).

17 is a conductor for applying a bias magnetic field to the MR element 18, and is made of metal such as AI, and is connected to the front and rear magnetic yokes 15. The IG is electrically and magnetically insulated via the insulating film 14 and is provided inside the notch 13, and its upper surface 17a is connected to the magnetic caulk 15.1 (similar to i, the flat surface 1 l b of the magnetic substrate 11 and the same height as the right.

19 is a sensor gap formed by the plane part 15b of the 1111 direction magnetic beam 15 and the plane part 1'Ga of the rear magnetic yoke 16 facing each other across the gear knob W1; Insulating film 1 between 19
4c, 14d and conductor iA+7 are intervening.

Figure 2 shows a3
As is clear from the figure, the sensor gap 19 is wider at the bottom than at the top. Reference numeral 20 denotes an insulating film made of, for example, S i 02, which is provided on the magnetic yoke 15, 16 and the conductor 17 with a plane at the same height as the plane 11b.
The element 18 is made of a Ni--Fe thin film, for example, and includes a magnetic flux detecting section 18a having a width P, and a connecting section 18b extending from the flux detecting section 18a.

These connecting portions 18b and 18c are provided with leads 19a and 19b, respectively. Width P
The magnetic flux detecting section 18a that detects the magnetic flux is provided one gap above the sensor 4 with the width W1 on the right side, with an insulating film 20 having a flat plane interposed therebetween.

In this example, W + =-3-4 μm, P = 2-3 μm
It goes without saying that these specific values will vary depending on the specifications.

As shown above, the structure of the present invention is most different from the conventional structure in that the gravitational magnetic yoke 15 and the intrusive magnetic yoke 1
This is the point where the MR mustard 18 is disposed on the sensor gap 19 formed by the planes 15b and 16a of the flange 1 of 6. In other words, the I
This is because the VI R element 18 is provided.

The operation of the above configuration is similar to that of the prior art example, so a description thereof will be omitted.

FIGS. 3(a) to 3(f) show the first structure shown in FIG. 1 which constitutes the present invention.
FIG. 2 is an explanatory view of the pre-processing process of the embodiment, and is explained based on a sectional view taken along the line II in FIG. 1.

The manufacturing process will be described below with reference to the same figure.

In FIG. 3(a), J3 is a magnetic substrate with a flat plane 31a on the upper surface.

32 is a groove formed in the plane 31, and the bottom 32a of the groove 32 is substantially parallel to the plane 31a and has a smooth plane. As a method for forming the groove 32, the resist 1 to portions on the substrate surface are formed into the groove 32 by lithography.
There is a method of etching using a solution such as phosphoric acid after removing (2).

As will be described later, the bottom 32a of the groove 32 needs to be smooth in order to provide a magnetic gap, but if an ion milling method using an inert gas such as argon is used as the etching method, the etching will be smooth. - It is possible to make the cutting surface smooth.

Next, as shown in Figure 3(b), △l 203°s r
The electrical insulator 33 of O2:q is stacked 11 times on the magnetic substrate 31 having the L groove 32 by spucking, vaporization, or other means.

Subsequently, after depositing a non-magnetic metal portion 35 such as Δl or Mo on the electrical insulator 33, the J14a metal body 35 is etched using the sensor gap pattern 34 formed by photolithography as a mask.

By using this wet undercutting method, the electric insulator 33 can be etched to form a rib, and the conductor 35a made of a non-magnetic metal portion shown by the dotted line can be etched.

First, the electrical insulator 33 is removed by using the sensor gap pattern as a mask to remove the non-magnetic metal portion 35a obtained by etching.
When 3 is provided, for example, by SiO2,
Plasma etching using CF4 can be used, and the magnetic substrate 31 can be used as the etching step.

As described above, from the non-magnetic metal part 35a provided in the groove part 32 of the magnetic substrate 31 via the electrical insulator 33)
Sensor gap pattern 34 consisting of l to l deviation 1-
After peeling off, as shown in FIG. 3(C), an electrical insulating film 36, which is to become the magnetic gap 14a, is deposited, and then a soft magnetic film 37, such as Sendust, which is to become the magnetic yoke 15, 16 is deposited. is deposited on the electrical insulating film 3C.

Thereafter, most of the deposited soft magnetic film 37 and electrical insulating film 36 (up to broken line 38) are removed by polishing, thereby obtaining a substrate 40 having a polished surface 39 as shown in FIG. 3(d). 37a and 37b are front and rear magnetic yokes, respectively, and 35a is a conductor for applying a bias current.

Next, as shown in FIG. 3(e), an electrical insulating film 41 made of 5i02 or the like is deposited on the polished surface 39 of the base 1fi40.
Furthermore, an MR element 42 made of, for example, Ni--Fe is formed thereon using sputtering means or the like. Thereafter, when the end portion 44 of the substrate 40 is cut along the broken line 43, the magnetic gap 3
Ga appears and the yoke type MR shown in Figs. 1 and 2
An Ml film head 50 equivalent to the thin film head 10 is obtained.

FIG. 3(f) does not show an example of the fVtRVt head in which a protective substrate 47 is provided on the plane having the MR element 42 in FIG. 3(e) via a protective WA 45 made of 5102 etc. and an adhesive layer 46. However, it can be seen that no level difference occurs in the adhesive layer 4G.

As described above, according to the present invention, when forming a pattern of magnetic coke, the pattern can be formed with good v1 degree because there are few steps. Since there are no steps on the magnetic yoke, there is no deterioration of magnetic properties. Even when a highly wear-resistant magnetic head is constructed by bonding a protective substrate to the magnetic yoke surface, there are no steps, so the adhesive layer can be made thinner. be able to,
This makes it possible to manufacture an MR thin film head that is not affected by wear of the adhesive layer.

FIG. 4 and FIG. 5 show the second and third embodiments of the present invention, respectively.
This is a cross-sectional view of an example of
The purpose is to form it near the MR element.

In FIG. 4, GO is the second embodiment MRNPa
It is the head. Reference numeral 61 denotes a second magnetic yoke made of a magnetic thin film such as Sendust, and in the MR thin film head 10 shown in FIG. The Si
MR element 18a via an electrical insulating film 62 made of O2 etc.
Place it on top.

63 is a second sensor gap provided on the second magnetic yoke 61, and by using the above patterning method, the second sensor gap having a gap length W2 can be formed on the MR element 18a with accuracy. It becomes possible to do so.

In FIG. 5, 70 is an MR thin film head of the third embodiment. Reference numeral 71 denotes a second magnetic yoke made of a magnetic thin film such as Sendamer 1-, which is not shown in FIG.
A sensor gap 72 having a gap length W3 is formed on the conductor 35a of the polished surface 39 of the sensor.

73 is an electrical insulating film made of 5i02 or the like provided on the second magnetic yoke 11, and 14 is an electrical insulating film Il! 73
This is an MR element provided on the sensor gap 72 via the sensor gap 72.

In this configuration, the sensor gap length W3 can be formed with high precision, and the surface unevenness of the second magnetic yoke 71 can be reduced compared to the second magnetic yoke 61 shown in FIG. This has an advantageous effect when the magnetic properties of the soft magnetic film constituting the magnetic film are extremely sensitive to surface irregularities.

(Effects of the Invention) As described above, the magnetoresistive thin film magnetic head according to the present invention has a groove section provided on a flat surface of a magnetic substrate having a flat section,
A magnetic yoke that has a sensor gap and is made of a ferromagnetic thin film and a conductor that provides a bias magnetic flux to the sensor gap are buried inside this groove, and the heights of these are the same as the flat part of the magnetic substrate. (1) By constructing the same plane by polishing, and providing the MR element near the sensor gap exposed on this same plane, (1)
Magnetic Yuke does not suffer from deterioration of magnetic properties due to differences in level, making it possible to manufacture an MR thin-film head with excellent reproduction efficiency.

■ When configuring the protective substrate with the magnetic yoke surface excluding the MR element, since the magnetic yoke surface is on the same plane except for the MR element, the adhesive layer on the tape old moving part can be made thinner. M not affected by wear due to tape running
Enables LJ construction of R thin film head.

In addition, by configuring the MR element in the vicinity of the second magnetic yoke surface metal part having the second sensor gap on the same plane, (1) a highly accurate connection between the sensor gap and the MR element; The present invention has the following effects, such as enabling the configuration and manufacturing of MR thin film heads with less variation in manufacturing.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of the first embodiment of the yoke-type MR thin film head according to the present invention, FIG. 2 is a sectional view of the main part along line 14 in FIG. a) to (e) are explanatory views of the manufacturing process of the embodiment of the yoke type MRii' film head according to the present invention, and FIG.
4 and 5 are cross-sectional views showing the second and third embodiments of the present invention, respectively. , FIG. 6 is a sectional view of a conventional yoke type magnetoresistive thin film magnetic head. 11...Magnetic substrate, 11a...Wall surface, 11b...
Plane, 12...Magnetic arc sliding part, 13...-Notch, 14, 20...Electric insulating film, 15.378...Front magnetic yoke, IG, 3'7b...Backward magnetic yoke , 17... Conductor, 18, 42.74... Magnetoresistive element (MR element), 19... Sensor gap, 61, 71... Second magnetism]-ri, G3.73... -Second sensor gap. Sai I 10,000 2l - t2 2'3 times

Claims (2)

[Claims] (1) Providing a magnetic substrate having a wall surface serving as a sliding surface for the magnetic tape and a plane formed almost perpendicular to this wall surface,
A notch having a flat part is formed on a plane including the wall surface, and a conductor for applying a bias magnetic field and a magnetic yoke having a sensor gap for applying magnetic flux to the magnetoresistive element are respectively connected to an electrical insulating film. The magnetoresistive element is arranged so that it is at the same height as the plane of the magnetic substrate, and the sensor gap is exposed on this plane, with an electrical insulating film serving as a magnetic gap interposed therebetween. A magnetoresistive thin film magnetic head, characterized in that it is disposed near the exposed surface of the sensor gap. (2) Providing a magnetic substrate having a wall surface serving as a sliding surface for the magnetic tape and a plane formed almost perpendicular to the wall surface,
A cutout portion having a flat portion is formed on a plane including the wall surface, and a conductor for applying a bias magnetic field and a first magnetic yoke having a first sensor gap for applying magnetic flux to the magnetoresistive element are provided. , are arranged so as to be at the same height as the plane of the magnetic substrate, and so that the sensor gap is exposed on this plane, via an electrical insulating film and an electrical insulating film to be a magnetic gap, respectively, 2
A magnetoresistive thin film magnet, characterized in that a second magnetic yoke having a sensor gap of is provided to cover the first sensor gap, and the magnetoresistive element is provided near the second sensor gap. head.