JPH0664695B2 - Method of manufacturing magnetic head - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head, and more particularly to a method of manufacturing a magnetic head using a magnetic material having an extremely high saturation magnetic flux density for a part of a magnetic pole.

[Background of the Invention]

In recent years, the magnetic recording technology has made remarkable progress by developing a high coercive force tape and a high performance magnetic head material for the tape. In particular, when a metal tape having a high coercive force is used, in a high recording density region of a recording wavelength of several μm to 1 μm or less, a marked increase in output and C / N
An increase in (output-noise ratio) is achieved, and a significant improvement in recording density is being achieved in fields such as VTRs that require high recording density. However, in the magnetic head using ferrite which has been used for the conventional VTR etc., the saturation magnetic flux density of ferrite is about 5000 gauss or less, so the magnitude of the recording magnetic field is not sufficient and a high coercive force metal tape is used. Therefore, a magnetic head using a metal magnetic material having a high saturation magnetic flux density has been required. As such a metal magnetic material, an Fe-Al-Si alloy (saturation magnetic flux density of about
10kG), Fe-Ni alloy (saturation magnetic flux density about 8kG), Fe-Si
Series alloy (saturation magnetic flux density about 18kG), Fe, Co, Ni
Of at least one of B, C, N, Al, Si, P, and the like, a metal-nonmetal amorphous alloy, Fe, Co,
There is a metal-metal amorphous alloy containing Y, Ti, Zr, Hf, Nb, Ta, etc. in at least one of Ni. Of these, the material with the highest saturation magnetic flux density is a Fe-Si alloy with a Si content of about 6% by weight, and its saturation magnetic flux density is about 18 kG.

On the other hand, the gap length of magnetic heads for VTRs in recent years has been narrowed down in order to realize high-density magnetic recording. The gap length, which was 0.5 μm in the past, was 0.3 μm in recent years, and 0.1 to 0.2 μm in the future. The gap length is required to be. As described above, when the gap length is narrowed, the strength of the magnetic field leaked from the head is significantly reduced.
Further, in recent years, in order to realize high-density magnetic recording, the coercive force of the magnetic recording medium has been increasing, and the coercive force of the conventional oxide magnetic tape of about 300 Oe has been increased to about 700 Oe.
With the advent of magnetic tapes using metallic magnetic powder in recent years, approximately 15
Even those with a coercive force of 00 Oe have been manufactured.
As described above, when a magnetic head having a small gap length is used for such a magnetic tape having an extremely high coercive force, the shortage of the recording ability especially in the long wavelength region poses a problem. A magnetic head material having a high magnetic flux density is required. In the future, the coercive force of the magnetic recording medium will further increase and the gap length of the magnetic head tends to be further narrowed, so that the demand for high saturation magnetic flux density of the magnetic head material will become stronger.

Further, in a magnetic head for perpendicular magnetic recording, which has been researched in recent years, in order to improve the recording density, the thickness of the main magnetic pole for recording / reproducing on / from the perpendicular magnetic recording medium must be extremely thin. As described above, when the main magnetic pole is extremely thin, magnetic saturation is likely to occur at the tip of the magnetic pole during recording, and when magnetic saturation occurs, recording on the perpendicular magnetic recording medium becomes difficult. In order to solve these problems, it is necessary to increase the saturation magnetic flux density of the magnetic material used for the main pole as much as possible.

Similar problems also exist in the case of the conventional in-plane recording thin film head used in a computer storage device or the like. That is, the thin film head has a smaller cross-sectional area of the magnetic pole in the vicinity of the working gap than the bulk type head, so that magnetic saturation easily occurs.
Therefore, there is a strong demand for a magnetic head material having a high saturation magnetic flux density even in a thin film head.

[Object of the Invention]

An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to form a magnetic pole of a magnetic head with a magnetic material having a saturation magnetic flux density higher than that of the conventional magnetic head, so that the magnetic head has better recording characteristics than the conventional magnetic head. It is to provide a manufacturing method of.

[Outline of Invention]

In order to achieve the above-mentioned object, the present invention comprises at least one of the magnetic poles of the magnetic head in the vicinity of the magnetic recording medium, which is in contact with the magnetic recording medium, and is made of iron or an iron-based magnetic alloy film. A region containing at least one element of nitrogen, carbon and boron is partially formed by an ion implantation method, and the saturation magnetic flux density of the element containing region is made higher than that of a conventional high saturation magnetic flux density magnetic material. As a result, a magnetic head having better recording characteristics than before can be obtained.

When an iron thin film is formed by vapor deposition or sputtering in an atmosphere containing nitrogen, under appropriate conditions,
It is known that a film with a saturation magnetic flux density higher than that of iron can be obtained (Solid State Physics, Vol.7, No.9 (1972) p.483 ~ 49
Five). However, in order to produce a film with a high saturation magnetic flux density by this method, a troublesome operation of accurately controlling the partial pressure of nitrogen in the atmosphere and the temperature of the sample is required. There is a problem that the density drops sharply.

The present invention solves the above problems by injecting and containing nitrogen in an iron or iron-based magnetic alloy film by an ion implantation method. When the ion implantation method is used, nitrogen per unit area of the film is reduced. There is an advantage that the content can be easily controlled, and therefore, a magnetic film having a high saturation magnetic flux density can be easily manufactured. Similar results are obtained with carbon or boron in addition to nitrogen.

An example of injecting nitrogen into iron or iron-based alloy by ion implantation is Phys. Status Solids, 80 (1) (198
3) pp. 211-222, but does not mention the magnetic properties of the obtained samples.

More specifically, in the magnetic head for perpendicular magnetic recording of the present invention, after the main pole is formed by using a thin film of iron or an iron-based magnetic alloy, the main pole is formed at least in the vicinity of the sliding surface of the magnetic recording medium. By implanting and containing at least one element of nitrogen, carbon and boron by the ion implantation method, the saturation magnetic flux density of the iron or iron-based alloy in the implanted portion is increased, and for perpendicular magnetic recording with extremely excellent recording characteristics. A magnetic head is obtained.

Further, in the magnetic head for longitudinal magnetic recording of the present invention,
At least the portion near the working gap forming surface of the magnetic head is made of iron or an iron-based magnetic alloy film, and the iron or iron-based magnetic alloy film on the working gap forming surface of the magnetic head is selected from nitrogen, carbon and boron by ion implantation. By injecting and containing one kind of element, the saturation magnetic flux density of iron or an iron-based magnetic alloy in the implanted portion is increased, and an in-plane recording magnetic head having excellent recording characteristics is obtained.

Another advantage of the magnetic head for longitudinal magnetic recording of the present invention is as follows. That is, when a magnetic film having a high saturation magnetic flux density is deposited on the working gap forming surface of the magnetic head by vapor deposition or sputtering, the interface between the magnetic substrate and the magnetic film having a high saturation magnetic flux density formed thereon is Since it becomes parallel to the gap surface, a contour effect occurs, but when a magnetic film having a high saturation magnetic flux density is formed on the operation gap forming surface by the ion implantation method as in the present invention, the concentration of the implanted element is increased. Is gradually changed in the depth direction, the saturation magnetic flux density is also gradually changed in the depth direction, and therefore, there is an advantage that the contour effect is unlikely to occur.

The above can also be applied to the ring type magnetic head for perpendicular magnetic recording.

As described above, the present invention provides a magnetic head having extremely excellent recording characteristics.

When the sample is heated to a temperature of 500 ° C. or lower and 70 ° C. or higher after ion implantation in the manufacturing process of the magnetic head of the present invention, a magnetic film having a high saturation magnetic flux density may be easily obtained in a stable manner. However, if the heating temperature is set to 500 ° C. or higher, the phase having a high saturation magnetic flux density may be decomposed and the saturation magnetic flux density may be decreased, which is not preferable.

It is generally known that iron and iron-based magnetic alloys containing magnetic elements such as nitrogen, carbon and boron, have magnetic anisotropy induced by heat treatment in a magnetic field.
This is because the infiltration type element in iron or the iron-based magnetic alloy moves to a position where the energy is reduced with respect to the magnetization direction and stabilizes the magnetization direction. When the induced magnetic anisotropy becomes large, the magnetic permeability decreases, which may not be preferable as a magnetic head. Further, it may be effective for the characteristics of the magnetic head to give an appropriate amount of magnetic anisotropy in a certain direction.

As described above, controlling the magnitude and direction of the induced magnetic anisotropy is necessary to obtain a magnetic head with excellent characteristics. The control of the induced magnetic anisotropy as described above can be performed by applying a magnetic field while heating the sample. Further, in the present invention, the induced magnetic anisotropy can be controlled by applying a unidirectional magnetic field or a rotating magnetic field to the surface of the sample during the ion implantation step.

Although the thickness of the ion-implanted layer formed by the ion-implantation method used in the present invention changes depending on the ion acceleration voltage, it is difficult to make the thickness of the ion-implanted layer about 1 μm or more. Therefore, in order to obtain an ion-implanted layer of about 1 μm or more, the step of forming a thin film of iron or iron-based magnetic alloy of 1 μm or less and the step of ion-implanting this film to form an ion-implanted layer are repeated a plurality of times. , And can be obtained by stacking ion-implanted layers. Further, a coercive force can be obtained by inserting a ferromagnetic or non-magnetic intermediate layer between each of these ion-implanted layers or as a plurality of ion-implanted layers as one ion-implanted layer block. Alternatively, magnetic properties such as magnetic permeability can be improved.

Example of Invention

 The present invention will be described in detail below with reference to examples.

Example 1 An iron thin film having a thickness of 0.15 μm was formed on a glass substrate by a sputtering method, then nitrogen ions were implanted into the iron thin film, and the substrate was heat-treated at 350 ° C. for 30 minutes. The average content of nitrogen in this iron film and the change in its saturation magnetic flux density are shown in FIG. As can be seen, the average nitrogen concentration in the iron layer with increasing nitrogen ion implantation amount is gradually increased, which since accompanied by saturation magnetic flux density of about 5 × 10 ¹ amount implantation of nitrogen ions ⁶ ions / cm ² , Ie average nitrogen concentration
At 12at%, the maximum increase is about 15%. When the average nitrogen concentration exceeds this value, the saturation magnetic flux density sharply decreases, and the average nitrogen concentration is 20at.
%, Equivalent to iron film. From the above results, it is understood that the saturation magnetic flux density has an effect of increasing the average nitrogen concentration Oat% to less than 20at%, more preferably in the range of 5at% to 18at%.

Next, FIG. 2 shows an outline of a method of manufacturing a perpendicular magnetic recording head using the above-mentioned magnetic film having a high saturation magnetic flux density as a main pole (see Japanese Patent Application No. 57-179854). As shown in FIG. 2 (a), the thickness of the main magnetic pole film was formed by the sputtering method on the non-magnetic substrate 1 made of photoceram (trade name of crystallized glass manufactured by Corning Glass Co., USA).
An iron thin film 2 having a thickness of 0.15 μm was deposited, and a pattern was formed in the shape of a head in which the width of the magnetic pole tip was narrowed to a predetermined track width. After that, 5 nitrogen ions are applied on the iron thin film 2.
× 10 ^{1 6} pieces / cm performs ion implantation with the ^second density, heating to perform the stabilization phase showing a high saturation magnetic flux density and at the same time to remove the distortion due to ion implantation and then at 350 ° C. 30 min, high saturation magnetic flux density The main magnetic pole film 2 of was prepared. further,
As shown in FIG. 2B, after a film 3 for reducing the magnetic resistance of the main magnetic pole film 2 is formed on the main magnetic pole film 2 by using a permalloy film, patterning is performed to form the main magnetic pole film 2. The permalloy film 3 near the tip is removed to a length of about 2 to 5 μm. Then, an insulating layer 4 made of SiO _{2 is} formed on the entire surface by a sputtering method so as to have a thickness of about 3 μm, and further thereon.
Al film is vapor-deposited by mask vapor deposition method, width 6μm, height 4.0
The spiral type Al winding 5 having a predetermined number of turns is formed with a thickness of μm, and then a resin layer 6 is applied and cured so as to fill the gap between the windings and at the same time coat the upper surface. An auxiliary magnetic pole 7 made of a -W-Zr-based amorphous magnetic alloy film was formed. A plan view of the perpendicular magnetic head thus manufactured is shown in FIG. In this figure, 1 is a non-magnetic substrate, 7 is an auxiliary magnetic pole, 5 is a winding, 8 is a lead wire portion of the winding 5, and 9 is a recording medium sliding surface.

Using the magnetic head manufactured in this example, Ce of Hc1000Oe
When recorded on -Cr perpendicular magnetic recording medium, as compared to the magnetic head which is not ion-implanted into the main magnetic pole, the recording density D _{5 0}
(Recording density at which recording / reproducing output is half that at low recording density) was increased by about 30%. As described above, in the magnetic head of the present invention, it was confirmed that the recording density can be improved by ion-implanting the main pole to give a high saturation magnetic flux density. It has been confirmed that when carbon or boron ions are implanted into the main magnetic pole made of iron or an iron-based magnetic alloy instead of nitrogen ions, the effect of improving the recording density is obtained as in the case of nitrogen ions.

Example 2 In the magnetic head using the magnetic thin film as described in Example 1, it is important to control the magnetic anisotropy of the magnetic thin film. In general, in a magnetic thin film, the magnetic permeability in the direction perpendicular to the easy magnetization direction tends to be larger than that in the easy magnetization direction. Therefore, the direction perpendicular to the direction in which the magnetic velocity flows in the magnetic head coincides with the easy magnetization direction of the magnetic thin film. It is better to configure it. In the magnetic head of the present invention, the magnetic anisotropy of the main pole can be controlled by performing ion implantation while applying a magnetic field. In this example, ion implantation was performed while applying a magnetic field of 50 Oe in the track width direction of the main magnetic pole film, that is, in the direction A of FIG. The conditions for ion implantation other than the magnetic field application were the same as in Example 1. Then, a magnetic head for perpendicular magnetic recording was manufactured by the same method as in Example 1, and recording was performed on the same Co—Cr perpendicular magnetic recording medium as in Example 1. The recording / reproducing output at this time was about 2 dB higher than that of the magnetic head in which no magnetic field was applied to the main magnetic pole film during the ion implantation process. As described above, it has been confirmed that it is effective to apply a magnetic field in the ion implantation step to control the magnetic anisotropy of the main magnetic pole film.

Example 3 As a magnetic head for in-plane magnetic recording, a method of manufacturing a magnetic head according to the present invention comprising Mn-Zn ferrite and a sputtered film of an iron-based magnetic alloy is schematically shown in FIG. The magnetic head of this embodiment has the structure described in JP-A-58-15513.

As shown in FIG. 4 (a), two substrates 11 made of Mn-Zn ferrite are prepared, and flat surfaces 13 are left at predetermined intervals on one surface 12 which should be the gap opposing surface, and the flat surfaces 13 are formed. Department
A pair of V-shaped grooves 14 adjacent to each other between 13 are formed by grinding or the like. In this case, the top of the inverted V-shaped projection 15 of the substrate 11 sandwiched between the pair of V-shaped grooves 14 adjacent to each other is set to be lower than the flat portion 23 by a predetermined length.

As shown in FIG. 4B, the surface of the substrate 11 on which the groove processing has been completed.
An iron film 16 having a thickness of about 10 μm is formed on the 12 side by a sputtering method.

As shown in FIG. 4C, a low melting point glass layer 17 was melted and formed so that at least the V-shaped groove 14 on the iron film 16 of the substrate 11 on which the iron film 16 was adhered was filled.

A substrate on which a glass layer 15 is formed as shown in FIG.
The glass layer side of 11 is ground and polished up to the flat portion 13. At this time, the iron film 16 on the tip portion of the inverted V-shaped projection 15 of the substrate 11 is partially polished and removed to be flat, and an operating gap forming surface 18 having a predetermined track width is obtained.

As shown in FIG. 4E, a winding window groove 19 is grinded at a right angle to the V-shaped groove 14 on one surface of the substrate 11 on the side having the iron film 16 after the step of FIG. Etc. to form the magnetic head core half block 20. The substrate 11 obtained in FIG. 4D is used as a magnetic head core half block 20 '. Next, nitrogen ions are added to the iron film portion 21 of the magnetic head core half block 20 near the operating gap on the operating gap forming surface 18 and the iron film portion of the magnetic head core half block 20 'corresponding to this.
× 10 ^{1 6} pieces / cm ² in density ion implantation, then deposited by a thickness of 0.15μm sputtered SiO ₂ film serving as the gap-forming layer to the working gap forming surface of the magnetic head core half blocks 20, 20 '.

As shown in FIG. 4 (f), the magnetic head core half blocks 20 and 20 'after the step shown in FIG. 4 (e) were butted against each other with their ion-implanted portions of the iron film facing each other. Above, by heating at 380 ° C. for 30 minutes, the glass layers 17 were fused and fixed, and the magnetic head core half blocks 20, 20 ′ were joined and integrated. Further, this heating strengthened the bond between nitrogen and iron implanted in the iron film and stabilized the magnetic film having a high saturation magnetic flux density. Then, by cutting the integrated magnetic head core half blocks 20 and 20 'along the alternate long and short dash lines, the magnetic head 22 as shown in FIG.
Is obtained. 23 is an operating gap.

Next, the winding window groove shown in Fig. 4 (e) for comparison.
In the magnetic head core half block 20 having 17 and the magnetic head core half block 20 'having no winding window groove, ion implantation is not performed, and other shapes are the same as those shown in FIG. A magnetic head was produced. When a signal with a wavelength of 5.8 μm is recorded on a metal tape having a coercive force Hc = 1500 Oe using these magnetic heads and the signal is reproduced using a conventional ferrite magnetic head, the magnetic head subjected to the above-mentioned ion implantation is , An output increase of about 1.5 dB was recognized as compared with the magnetic head which was not ion-implanted. Such an effect of improving the recording characteristics was obtained by implanting carbon or boron ions instead of nitrogen ions.

〔The invention's effect〕

As described above, in the magnetic head for perpendicular magnetic recording, at least the operation of iron or iron-based alloy used near the sliding surface of the magnetic recording medium of the main magnetic pole film and in the in-plane magnetic recording head on the operation gap forming surface side. By introducing at least one element of nitrogen, carbon and boron into the vicinity of the gap by ion implantation, it is possible to improve the saturation magnetic flux density of iron or an iron-based alloy and obtain a magnetic head with extremely excellent recording characteristics. did it.

[Brief description of drawings]

FIG. 1 is a diagram showing changes in the average nitrogen concentration and the saturation magnetic flux density in the iron film with respect to the implantation amount of nitrogen ions into the iron film,
FIG. 2 is a schematic diagram for explaining a method of manufacturing a magnetic head for perpendicular magnetic recording according to an embodiment of the present invention, and FIG.
FIG. 4 is a plan view of the magnetic head for perpendicular magnetic recording obtained by the drawing, and FIG. 4 is a schematic explanatory view of a method of manufacturing a magnetic head for in-plane magnetic recording which is another embodiment of the present invention. In the figure, 1 ... Non-magnetic substrate, 2 ... Main magnetic pole film 3 ... Permalloy film, 4 ... Insulating layer 5 ... Winding, 6 ... Resin layer 7 ... Auxiliary magnetic pole, 8, 8 '... Lead wire 9 …… Sliding surface of magnetic recording medium 11 …… Mn-Zn ferrite substrate 12 …… One surface of the substrate 11 that should face the gap 13 …… Flat part, 14 …… V-shaped groove 15 …… Substrate 11 inverted V-shaped protrusions 16 ... Iron film, 17 ... Glass layer 18 ... Gap forming surface of iron film 16 ... Winding window groove 20, 20 '... Magnetic head core half block 21 ... ... Nitrogen ion implantation part of iron film 16 ... Magnetic head

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Ryo Suzuki 1-280 Higashi Koigakubo, Kokubunji City, Tokyo Metropolitan Research Laboratory, Hitachi, Ltd. Central Research Laboratory (56) Reference JP 58-105422 (JP, A) JP 58-189816 (JP, A) JP 56-159820 (JP, A) JP 52-4805 (JP, A) A) Japanese Patent Publication Sho 47-40756 (JP, B1)

Claims (7)

[Claims] 1. A step of forming iron or a magnetic metal film containing iron as a main component in the vicinity of at least one of the magnetic poles in contact with the magnetic recording medium, and an ion implantation method on at least a part of the magnetic metal film. Average content concentration of at least one element selected from nitrogen, carbon and boron
After containing less than 20 atomic%, a heat treatment is performed to form at least a magnetic pole made of a magnetic metal film having a saturation magnetic flux density higher than that of the magnetic metal film alone. Production method. 2. The method of manufacturing a magnetic head according to claim 1, wherein the magnetic metal film is a magnetic alloy containing iron as a main component. 3. The method for manufacturing a magnetic head according to claim 1, wherein the magnetic metal film is pure iron. 4. The method according to any one of claims 1 to 3, characterized in that at least one element selected from nitrogen, carbon and boron is contained by the ion implantation method at an average content concentration of 5 atom% to 18 atom%. A method of manufacturing a magnetic head according to any one of items. 5. Manufacturing of the magnetic head according to claim 1, wherein after the ion implantation, heat treatment is performed at a temperature of 500 ° C. or less. Method. 6. The method according to claim 1, further comprising the step of applying a magnetic field rotating in the film surface of the magnetic metal film relative to the film surface during the ion implantation. 5. The method for manufacturing a magnetic head according to any one of items 5. 7. The method according to claim 1, further comprising the step of applying a magnetic field rotating relative to the film surface of the magnetic metal film while performing a heat treatment after the ion implantation. 7. The method of manufacturing a magnetic head according to any one of items 1 to 6.