JP2002140803A - Magnetic head, its manufacturing method, and magnetic disk device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new magnetic head structure for permitting high-density recording, its new manufacturing method, and a high-performance magnetic disk device using the magnetic head. SOLUTION: A magnetic circuit directly connects a nonmagnetic metal gap layer, a high Bs track magnetic layer, an upper magnetic core, a high Bs back contact magnetic layer, and a lower magnetic core. A part of a coil is formed in an insulating material in the circuit. The high Bs track magnetic layer, the high Bs back contact layer, and the upper face of the coil insulating material form a plane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a magnetic head used for writing magnetic recording on a hard disk and a magnetic head using the same, and further relates to a hard disk drive using the magnetic head. .

[0002]

2. Description of the Related Art As is well known to those skilled in the art, a hard disk drive comprises a magnetic disk disk as a magnetic recording medium, a write magnetic head for writing and reading magnetic recording signals to and from the disk, and a magnetic head. The main components include a servo mechanism for accessing a predetermined position on the disk, an electric circuit for signal processing, and the like. One of the most important items of the performance of the hard disk device is the areal recording density. To improve the areal recording density, it is necessary to increase the linear recording density and the track density.

Of these, it is essential to reduce the track width in the track portion of the write magnetic head in order to improve the track density, and it is necessary to reduce the leakage magnetic flux during writing. The technical problems required for such a write magnetic head are described in detail in, for example, Nikkei Electronics, and a structural example of a track portion is described in US Pat. No. 5,285,340.

The insulating material used for the coil portion of the magnetic head for writing is usually a baked product of a positive type photoresist. To form such an insulating material, the insulating material must be maintained at a high temperature of about 200.degree. It is common sense to hold time.

[0005]

However, these prior arts have not been established as a specific manufacturing process of the entire head including a magnetic circuit and a coil for driving the magnetic circuit. Since the structure is not optimized, there is a problem that it cannot be said that the magnetic head is actually manufactured to provide a high-performance hard disk drive at a low cost.

In other words, it is not sufficient to manufacture only the tip of the track portion for manufacturing a write magnetic head. A series of manufacturing processes including a coil portion, an upper magnetic core portion and the like are rationally constituted, There is a need to overcome the difficulty of adapting materials optimized for meeting the required properties of the head to the manufacturing process.

In addition, since the thermal stability of the read head for high recording density is not sufficient, it is necessary to configure the process at a temperature as low as possible in the manufacture of the write head, which is a process after the formation of the read head. is there. Such a problem is caused by MR (Magneto-Resistive) in the read head.
Higher output GMR (Giant
With the use of Magneto-Resistive) sensors,
It becomes a more serious problem. Although the temperature range desired from the thermal stability of the sensor is below about 200 ° C., and preferably below 150 ° C., no reasonable manufacturing method has been provided for manufacturing write heads at such low temperatures. Was.

In view of the above problems, a first object of the present invention is to provide a magnetic recording medium including a track section, a coil section, an upper magnetic core section, and the like, which are rationally configured to simultaneously respond to the above-mentioned various problems. It is to provide a series of manufacturing processes for manufacturing a head.

A second object of the present invention is to provide a series of manufacturing processes for manufacturing a write magnetic head at a low temperature of 250 or less, preferably 200 ° C. or less. A third object of the present invention is to provide an optimal combination of magnetic head materials suitable for the manufacturing process.

A fourth object of the present invention is to provide a structure of a high-performance magnetic head for writing using the process and the material.

A fifth object of the present invention is to provide a high-performance magnetic disk drive using the magnetic head.

[0012]

As means for solving the above-mentioned problems, the present invention uses the following means. The present invention will be described in detail with reference to FIG.

FIG. 1A shows a lower magnetic core 1 of a write magnetic head.

On the lower magnetic core 1, a gap layer of a two-layer metal of a non-magnetic high melting point metal 2 and a non-magnetic gap metal 3 is formed by sputtering or the like, and this is shown as (b).

Next, the gap layer other than the track portion is removed by means such as milling (c). Next, a photoresist frame is formed so that plating can be performed on the track portion and the back contact portion, and a high Bs material 5 is formed by plating. After that, the frame resist is removed (d)
And

Next, an insulating material 6 is formed by sputtering or the like so as to cover the high Bs material 5 in the track portion and the back contact portion (e).

Next, a driving coil 7 is formed on the insulating material 6 (f).

Next, a coil insulating material 8 is formed to completely cover the coil 7 (g).

Next, a high B value is obtained by a technique such as chemical mechanical polishing.
Polishing is performed so that the material 5 and the insulating material 8 are on the same plane (h).

Next, the upper magnetic core 5 is connected to the exposed high Bs material 5 at the track portion and the back contact portion.
Forming 9 (i).

Next, an insulating material 10 is formed so as to cover the entire write head including the upper magnetic core 9, the coil 7, and the gap (j).

Finally, the head is completed by cutting and polishing so that the air bearing surface 11 is exposed. Needless to say, in order to ensure the performance as a magnetic head, even after the above steps, steps such as formation of a protective film and rail processing of the air bearing surface are required.

The above-described series of steps (a) to (j) are performed in order, whereby the gap layer, the high Bs track magnetic layer, the upper magnetic core, and the high Bs back contact magnetic layer of the nonmagnetic metal of the present invention are obtained. A magnetic closed circuit in which the lower magnetic core is directly connected, a part of the coil formed in the insulating material in the closed circuit, and a high Bs track magnetic layer, the high Bs back contact magnetic layer, and the coil insulating material. A magnetic head characterized in that the upper surface is flat can be manufactured.

The present invention can be manufactured using a series of processes and materials as described above, but there is a close relationship between each process and the relationship before and after each process and the materials used in each process.

Normally, in a composite head in which a read MR head and a write head are separated, the lower magnetic core 1
Also serves as the upper shield of the head. However, the present invention can also be used for manufacturing a so-called inductive thin film head in which the read and write heads are the same.

The lower magnetic core 1 of the present invention has a saturation magnetic flux density of 0.5 to 2.2 T Ni-Fe alloy or Co.
-Ni-Fe alloys or soft magnetic alloys containing these and other elements can be used.

The lower magnetic core 1 has a thickness of 0.5 to 5.
It is recommended that it be 0 μm. The upper and lower limits of the thickness are determined because the writing characteristics or the shielding effect as the composite head can be sufficiently ensured.

Further, the lower magnetic core 1 is not limited to a single layer, and the lower magnetic core 1 has a saturation magnetic flux density of 0.5 to 1.5.
T soft magnetic material, the upper part of which has a saturation magnetic flux density of 1.5 to 2.2
A soft magnetic two-layer structure of T may be used, and such a configuration may be more preferable than a single-layer structure.

In such a case, the ratio of the thicknesses of the upper portion and the lower portion is preferably set in the range of 1:10 to 1: 2 from the viewpoint of writing characteristics.

The non-magnetic high melting point metal 2 of the present invention is Cr, T
It is a non-magnetic metal mainly composed of i, Ta, Nb and the like. In the present invention, it is mainly used for ensuring the adhesion between the lower magnetic core 1 and the non-magnetic gap metal 3 and ensuring electrical conduction.
Therefore, when the adhesion can be ensured, the nonmagnetic high melting point metal 2 can be omitted.

The non-magnetic bonding metal 3 of the present invention is a material which forms a magnetic gap and secures close contact with the high Bs material 5. Further, in order to determine an accurate gap thickness by polishing the air bearing surface described later. Therefore, a material having excellent workability is required. From this point of view, it is desirable to use a metal having a Vickers hardness of about 500 or more, which is hard to corrode, and which has excellent bondability with the upper and lower layers, from the viewpoint of the nonmagnetic gap metal 3. As an example of such a metal, it is preferable to use a metal such as Pd, Rh, and Pt or an alloy containing these as a main component.

Further, from the viewpoint of gap formation, the total thickness of the nonmagnetic high melting point metal 2 and the nonmagnetic contact gap group 3 is 0.1
To 0.5 μm. The upper and lower limits of the thickness are usually limited to ensure the write performance of the head.

The removal of the non-magnetic refractory metal 2 and the non-magnetic contact gap group 3 other than the track portion of the present invention is desirable and necessary in order not to form an unnecessary gap in the magnetic circuit.

In order to remove such a gap layer, a resist is formed in a portion to be removed in advance, a non-magnetic high melting point metal 2 and a non-magnetic gap metal 3 are formed on the entire surface by means such as sputtering, and then the resist is removed. It is also possible to use a so-called lift-off method for simultaneously removing the non-magnetic high melting point metal 2 and the non-magnetic contact gap 3 on the resist. Such elimination methods are selected primarily for their economics.

The high Bs material 5 of the present invention is made of a Ni—Fe alloy or a Co—N alloy having a saturation magnetic flux density of 1.5 to 2.0 T.
An i-Fe alloy or a soft magnetic alloy containing these and other elements can be used.

The magnetic material of the high Bs material 5 in the track portion has a track width of 0.2 to 2.0 μm and a thickness of 0.2 to 2.0.
It is desirable to form it to 0 μm. The width and thickness of such a magnetic material are determined from the necessity of maintaining the recording density and the recording speed in appropriate ranges, and can be easily manufactured by the method of the present invention.

When plating the track portion and the back contact portion, a frame surrounding the track portion and the back contact portion is formed, and plating is performed on the portions other than the track portion and the back contact portion so that the track portion and the back contact portion are plated. A method known to those skilled in the art can be used, such as removing unnecessary portions of the plating by etching while protecting with a cap resist and removing the frame resist.

As the insulating material 6 of the present invention, an oxide insulating material such as alumina, silica or the like is preferably used, but this does not mean that an insulating material other than oxide is not used.

In forming the coil 7 of the present invention, a base film for coil plating is formed on the surface of the flattened high Bs material 5 and the insulating material 6 by sputtering or the like, and a frame resist for coil plating is formed. 7 is formed of a low-resistance metal such as Cu,
A method known to those skilled in the art for removing the exposed base film for coil plating by milling or the like after removing the frame resist can be used.

The coil insulating material 8 of the present invention comprises alumina,
An oxide insulating material such as silica is preferably used, but this does not mean that an insulating material other than oxide is not used.

Conventionally, a material obtained by baking a positive photoresist with the insulating material is used. However, in the present invention, an oxide such as alumina or silica which can be sputtered at room temperature to 150 ° C. or less is used as the insulating material, and This is polished.

In the polishing process of the present invention, the high Bs material 5 and the insulating material 8 are polished so as to be flush with each other by a method known to those skilled in the art such as chemical mechanical polishing.

In forming the upper magnetic core 9 of the present invention, a photoresist frame is formed after sputtering (not shown) of a plating base film, and plating in a magnetic field is performed to secure the magnetic anisotropy of the upper magnetic core 9. After forming the cap resist in the required portion after plating, the plating of the unnecessary portion is removed by etching, the frame resist is removed, and then the plating base film is removed by milling. be able to.

The upper magnetic core 9 has a saturation magnetic flux density of 0.
5 to 1.5T Ni-Fe alloy or Co-Ni-
An Fe alloy or a soft magnetic alloy containing these and other elements can be used.

As the insulating material 10 of the present invention, an oxide insulating material such as alumina or silica is preferably used, but it is not necessarily the case that an insulating material other than oxide is not used.

The method for realizing the present invention and solving the conventional problems is not limited to the method described above, but may employ a manufacturing method as shown in FIG. FIG. 2 shows a case where the magnetic head is manufactured in a process different from that of FIG. 1 after manufacturing up to FIG. 1E, and FIG. 2 shows a manufacturing process after FIG. 1E. It is.

FIG. 2 (k) shows a step of forming the coil. The formation of the driving coil 7 on the insulating material 6 is the same as that of FIG. The coil 7 is formed linearly only in a portion corresponding to a lower portion of the upper magnetic core 9 to be referred to as (k).

Next, the entire surface is covered with an insulating material 8 to obtain (l).

Then, high B is applied by a technique such as chemical mechanical polishing.
Polishing is performed so that the s material 5 and the insulating material 8 are on the same plane (m).

Next, the upper magnetic core 5 is connected to the exposed high Bs material 5 at the track portion and the back contact portion.
9 is formed (n).

Next, the entire surface is covered with the insulating material 12 to obtain (o).

Next, the coil 7 is formed on the insulating material 12. At this time, the upper and lower coils are connected outside the upper magnetic core 9 (p).

Next, an insulating material 10 is formed so as to cover the entire write head including the upper magnetic core 9, the coil 7, and the gap (q).

Finally, the head is completed by cutting and polishing so that the floating surface 11 is exposed. In this case, in order to ensure the performance as a magnetic head, it is needless to say that a step of forming a protective film and a step of forming rails on an air bearing surface are necessary even after passing through the step of FIG. Absent.

The sequence of steps from FIG. 2 (k) to FIG. 2 (q) following the above-mentioned steps (a) to (e) in FIG. A magnetic closed circuit in which the high Bs track magnetic layer, the upper magnetic core, the high Bs back contact magnetic layer, and the lower magnetic core are directly connected, and a part of the coil is formed in an insulating material in the closed circuit. A magnetic head can be manufactured. According to the method shown in FIG. 2, the magnetic flux of the coil can be more efficiently converted to the magnetization of the upper magnetic core 9, so that a magnetic head having excellent electromagnetic conversion efficiency can be obtained. Further, the method of FIG. 2 has a great advantage that the area of the magnetic head can be remarkably reduced, so that the number of heads that can be manufactured by processing one wafer is remarkably increased.

[0056]

Embodiments of the present invention will be described below. FIG. 3 is a plan structural view of the magnetic head corresponding to the sectional structural view of FIG. 1 described above. In order to make the explanation easy to understand, FIG. 3 shows several layers constituting the magnetic head in an overlapping manner.

FIG. 4 is a sectional view of the air bearing surface shown in FIG.

The lower magnetic core 1 of the present invention is arranged as shown in FIG. The lower magnetic core 1 functions as an upper shield of the MR element 15 arranged below the lower magnetic core 1.

More specifically, M is placed on a lower shield 14 formed on a wafer 13 made of a material such as alumina titanium carbide.
After the formation of the R element 15, the upper shield (lower magnetic core 1) of the MR element 15 is formed to obtain the lower magnetic core 1 of the present invention.

As an example of the lower magnetic core 1 of the present invention, a Ni—Fe soft magnetic alloy having a saturation magnetic flux density of 1.0 T can be used. Such a soft magnetic alloy is a permalloy alloy having a Ni composition of about 80%, and its properties and production method are well known to those skilled in the art.

The thickness of the lower magnetic core 1 is, for example, 3.
0 μm.

Alternatively, the lower magnetic core 1 is not limited to a single layer. The upper portion is made of a high Bs soft magnetic material having a saturation magnetic flux density of 1.5 T at the upper portion and 0.5 μm at the upper portion, and the lower portion has a saturation magnetic flux density of 1. The low Bs soft magnetic material of 0T is a film having a two-layer structure having a thickness of 2.5 μm. When such a two-layer film is selected, the gap magnetic field strength at the time of writing can be improved, so that the characteristics of the head can be further improved. However, the number of manufacturing steps increases in order to form two layers as compared with a single layer, and it is necessary to determine which one to select from the viewpoint of the performance of the head and the required price for manufacturing the head. Because

The high Bs for the lower magnetic core used in the present invention
As the soft magnetic material, a Ni—Fe soft magnetic alloy having a Ni composition of about 46% can be used.

The non-magnetic high melting point metal 2 and the non-magnetic gap metal 3 used in the present invention are formed of a two-layer metal gap layer, for example, as shown in the shape of the non-magnetic gap metal 3 in FIG. Is formed in a shape surrounding.

As the high Bs material 5 of the track portion and the back contact portion used in the present invention, for example, a Ni--Fe soft magnetic alloy having a saturation magnetic flux density of 1.5 T and a Ni composition of about 46% can be used. . In the track portion, a high Bs material is formed by plating so that the track width W is 1.0 μm. In the present invention, the photoresist for forming the plating of the track portion can be formed on the substantially flat surface including the lower magnetic core 1 and the gap layer, so that it is possible to form the photoresist with extremely high precision, and as a result And precise control of the track width becomes possible.

According to the present invention, the driving coil 7 is formed on alumina as an insulating material. The coil height and width are each 3.0
μm is awarded. Also, the number of turns of the coil should be determined from the design of the head, and eight turns are selected as an example. Further, the coil is not limited to a single layer, but may be formed in two layers to prevent an increase in the head area due to an increase in the number of turns. To form such a coil, Cu /
After forming a coil plating base film such as Cr on the entire surface by sputtering or the like, forming a coil plating frame resist, forming the coil 7 by plating, removing the frame resist, and removing the exposed coil plating base film. It may be removed by milling or the like.

According to the present invention, the coil 7 is embedded by sputtering of alumina to form an insulating material 8 for the coil. Since such an insulating material can be formed at room temperature, no thermal problem occurs.

In the present invention, polishing is performed by chemical mechanical polishing so that the insulating material 8 for the coil and the high Bs material 5 of the track portion and the back contact portion are flush with each other. Specifically, the initial thickness of the high Bs material 5 and the initial thickness of the alumina are set to 4.0 μm or more in anticipation of the reduction by polishing so that the coil is coated with alumina after polishing. It is necessary to devise a method to stop the polishing when it becomes. In such polishing, precise control of the film thickness can be made possible by polishing using a slurry containing alumina polishing abrasive grains and nitric acid.

According to the present invention, the exposed upper magnetic core 9 has a high Bs
The material 5 is formed so as to be connected to the track portion and the back contact portion. As the upper magnetic core 9, for example, a Ni--Fe soft magnetic alloy having a saturation magnetic flux density of 1.0T can be used. In the formation of the upper magnetic core 9 of the present invention, a photoresist frame is formed after sputtering (not shown) of a base film for plating, and plating in a magnetic field is performed to secure magnetic anisotropy of the upper magnetic core 9. It is possible to use a method known to those skilled in the art such as forming a cap resist on the required portion, removing the plating of the unnecessary portion by etching, removing the frame resist, and then removing the plating base film by milling. . To ensure good magnetic anisotropy, a magnetic field of 0.1 T may be applied as an example.

In the present invention, the entire write head including the upper magnetic core 9 and the coil 7 is covered with alumina insulating material.
Complete the write head process.

A block including a plurality of heads is cut out from a wafer on which a large number of such heads are formed, and the air bearing surface is polished,
The head protection film is formed, the rail surface is processed on the air bearing surface, and the head is divided into a single head to complete a magnetic head.

FIG. 5 shows a magnetic head manufactured as described above.
16 shows an example of a method of incorporating 16 into a magnetic disk drive. The magnetic head 16 of the present invention has a structure in which it is mounted on a suspension 17 in advance and driven by a servo actuator 18. A plurality of magnetic disks 19 as recording media are rotated by the same cylinder. It is well known to those skilled in the art that usually two magnetic heads are mounted on one magnetic disk in order to use both sides of the disk as a recording medium. The magnetic disk device is completed by such a method.

The magnetic disk drive of the present invention uses the magnetic head of the present invention, and has a track recording density of 20 kTP by using a magnetic disk having a medium having a coercive force of 2000 Oersts and a rotation speed of 4000 rpm.
I (track per inch), linear recording density 260 kBPI
It is possible to achieve extremely excellent recording performance with a recording density of 5.2 Gbit / square inch in (bits per inch).
Therefore, it was found that a magnetic disk drive having a high recording density of 3 Gbits / square inch or more can be easily manufactured in the present invention.

FIG. 6 shows another embodiment of the present invention. FIG. 7 is a diagram showing the shape of the track portion on the air bearing surface as viewed from the X direction in FIG. In such a case, a photoresist frame is formed so that the upper track portion and the back contact portion of the lower magnetic core 1 can be plated, and a part of the high Bs material 5 is formed by plating. Thereafter, the nonmagnetic gap metal 3 is formed only on the track portion by plating, and the remaining part of the high Bs material 5 is formed on the track portion and the back contact portion again by plating. Thereafter, the magnetic head is manufactured in the same steps as in FIG. According to the method of the present invention, it is possible to form a head having extremely small leakage magnetic flux in the lateral direction on the track portion at a low temperature. Such a magnetic head is particularly preferable for miniaturizing the track width.

FIG. 8 shows another embodiment of the present invention. In such a case, in the polishing step, not only the high Bs material 5 and the insulating material 8 but also the coil 7 is polished so that the upper surfaces thereof are flush with each other. After the flattening, an insulating film 20 of alumina or the like is formed on the upper portion of the coil by sputtering or the like, and thereafter, the magnetic head is manufactured in the same steps as in FIG. It is recommended that the thickness of the insulating film 20 be 0.1 to 1.0 μm. According to the method of the present invention, a magnetic head in which the coil and the upper magnetic core are close to each other can be formed at a low temperature. Since such a magnetic head is easy to drive, it is particularly preferable for high-speed magnetic recording.

FIG. 9 shows another embodiment of the present invention. FIG. 10 is a diagram showing the shape of the track portion on the air bearing surface as viewed from the X direction in FIG. Even in such a case, a high Bs material is used in the polishing process.
Polishing is performed so that the upper surfaces thereof including not only the coil 5 and the insulating material 8 but also the coil 7 are flush with each other. After the flattening, an insulating film 20 of alumina or the like is formed on the coil and the track portion by sputtering or the like, and thereafter, the magnetic head is manufactured in the same process as in FIG. It is recommended that the thickness of the insulating film 20 be set to the gap thickness. According to the method of the present invention, a magnetic head which also serves as an insulating film for a coil and a gap can be formed at a low temperature. Since such a magnetic head is also easy to drive, it is particularly preferable for high-speed magnetic recording.

[0077]

The present invention simultaneously provides a method of manufacturing a high-performance magnetic head in a very simple process and a novel magnetic head structure. The use of the magnetic head of the present invention provides a very high-performance magnetic head. Since the disk device can be provided at a low cost, there is an immeasurable economic effect.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a manufacturing process of a magnetic head according to the present invention, using a cross-sectional view.

FIG. 2 is a diagram illustrating a manufacturing process of another magnetic head according to the present invention, using a cross-sectional view.

FIG. 3 is a diagram illustrating a structure of a magnetic head according to the present invention using a plan view.

FIG. 4 is a view for explaining the structure of the air bearing surface of the magnetic head according to the present invention by using a cross-sectional view.

FIG. 5 is an external view of a magnetic disk drive using the magnetic head of the present invention.

FIG. 6 is a diagram illustrating a structure of another magnetic head according to the present invention, using a cross-sectional view.

FIG. 7 is a diagram illustrating a track portion of the magnetic head according to the present invention of FIG. 6 in a structure viewed from an air bearing surface;

FIG. 8 is a diagram illustrating a structure of another magnetic head according to the present invention using a cross-sectional view.

FIG. 9 is a diagram illustrating a structure of another magnetic head according to the present invention using a cross-sectional view.

FIG. 10 is a diagram illustrating a track portion of the magnetic head according to the present invention of FIG. 9 in a structure viewed from an air bearing surface;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Lower magnetic core, 2 ... Non-magnetic high melting point metal, 3 ... Non-magnetic gap metal, 4 ... Back contact part, 5 ... High Bs
Material, 6: insulating material, 7: coil, 8: coil insulating material, 9:
Upper magnetic core, 10: insulating material, 11: floating surface, 12: insulating material, 13: wafer, 14: lower shield, 15: MR
Element, 16: magnetic head, 17: suspension, 18
... servo actuator, 19 ... magnetic disk, 20 ...
Insulating material.

 ────────────────────────────────────────────────── ─── Continued on the front page F-term (reference) 5D033 BA01 BA03 BA07 BA08 BA21 BA22 BA37 BA42 CA02 CA05 DA01 DA03 DA04 DA07 DA08 DA31

Claims (32)

[Claims] 1. A magnetic circuit in which a gap layer of a non-magnetic metal, a high Bs track magnetic layer, an upper magnetic core, a high Bs back contact magnetic layer, and a lower magnetic core are directly connected, and a coil is provided in an insulating material in the circuit. Forming a part and the high Bs
A magnetic head, wherein the top surfaces of the track magnetic layer, the high Bs back contact magnetic layer, and the coil insulating material are plane. 2. A magnetic closed circuit in which a gap layer of a non-magnetic metal, a high Bs track magnetic layer, an upper magnetic core, a high Bs back contact magnetic layer, and a lower magnetic core are directly connected, and an insulating material in the closed circuit. A part of the coil is formed above the upper magnetic core to form another part of the coil, and the high Bs track magnetic layer, the high Bs back contact magnetic layer, and the upper surface of the coil insulating material are flat. Magnetic head. 3. A magnetically closed circuit in which a gap layer of a non-magnetic metal, a high Bs track magnetic layer, an upper magnetic core, a high Bs back contact magnetic layer, and a lower magnetic core are directly connected and an insulating material in the closed circuit. A part of the coil forms another part of the coil above the upper magnetic core, and the high Bs track magnetic layer, the high Bs back contact magnetic layer, the coil, and the upper surface of the coil insulating material form a plane. A magnetic head, characterized in that: 4. A magnetic head according to claim 1, wherein the insulating material in contact with said coil is alumina or silica. 5. The magnetic head according to claim 1, wherein the insulating material in contact with the coil is formed at room temperature to 200 ° or less. 6. The lower magnetic core according to claim 1, wherein said lower magnetic core is Ni-
A magnetic head comprising a Fe alloy, a Co-Ni-Fe alloy, or a soft magnetic alloy containing these and other elements. 7. The lower magnetic core according to claim 6, wherein said lower magnetic core has a thickness of 0.5 mm.
A magnetic head having a thickness of 5 to 5.0 μm. 8. The lower magnetic core 1 according to claim 6, wherein the lower portion is a soft magnetic material having a saturation magnetic flux density of 0.5 to 1.5 T and the upper portion is a soft magnetic material having a saturation magnetic flux density of 1.5 to 2.2 T. A magnetic head having a two-layer structure. 9. The magnetic head according to claim 8, wherein a ratio of a thickness between an upper portion and a lower portion of the lower magnetic core having the two-layer structure is 1:10 to 1: 2. 10. A magnetic head according to claim 1, wherein said nonmagnetic metal gap layer is a laminate of a nonmagnetic high melting point metal and a nonmagnetic bonding metal. 11. A magnetic head according to claim 10, wherein said nonmagnetic metal gap layer has a thickness of 0.1 to 0.5 μm. 12. The non-magnetic high melting point metal according to claim 10, wherein
A magnetic head comprising r, Ti, Ta, Nb, or an alloy thereof. 13. A magnetic head according to claim 10, wherein said magnetic bonding metal is Pd, Rh, Pt, or an alloy thereof. 14. A magnetic head according to claim 1, wherein said high Bs magnetic layer is a soft magnetic alloy having a saturation magnetic flux density of 1.5 to 2.2T. 15. The high Bs magnetic layer according to claim 14, wherein
A magnetic head comprising a Fe alloy, a Co-Ni-Fe alloy, or a soft magnetic alloy containing these and other elements. 16. The magnetic head according to claim 15, wherein the high Bs magnetic layer has a track width of 0.2 to 2.0 μm. 17. A step of forming a non-magnetic metal gap layer in a track portion on a lower magnetic core, a step of forming a high Bs magnetic layer in a track portion and a back gap portion by plating, and exposing non-magnetic portions other than the track portion. Removing a metal gap layer, covering the high Bs magnetic layer formed in the track portion and the back gap portion with an insulating material, forming a coil on the insulating material, embedding the coil with the insulating material Polishing the insulating material and the high Bs magnetic layer from the surface to flatten the surface and expose the high Bs magnetic layer, and forming an upper magnetic core in contact with the high Bs magnetic layer at a track portion and a back contact portion. And a method for manufacturing a magnetic head. 18. A step of forming a nonmagnetic metal gap layer on a track portion on a lower magnetic core, a step of forming a high Bs magnetic layer on a track portion and a back gap portion by plating, and exposing a nonmagnetic portion other than the track portion. Removing the metal gap layer, covering the high Bs magnetic layer formed in the track portion and the back gap portion with an insulating material, forming a coil on the insulating material, and embedding the coil with the insulating material Polishing the insulating material, the high Bs magnetic layer, and the coil from the surface to flatten the surface to expose the high Bs magnetic layer and the coil; forming an insulating layer on the coil portion; B
forming an upper magnetic core in contact with the s-magnetic layer at the track portion and the back contact portion. 19. A method of manufacturing a magnetic head according to claim 17, wherein said lower magnetic core is a soft magnetic alloy having a saturation magnetic flux density of 0.5 to 1.5 T. 20. The lower magnetic core according to claim 19, wherein the lower magnetic core is Ni-
A method for manufacturing a magnetic head, comprising a Fe alloy, a Co-Ni-Fe alloy, or a soft magnetic alloy containing these elements and other elements. 21. A method according to claim 19, wherein said lower magnetic core has a thickness of 0.5 to 5.0 μm. 22. The lower magnetic core 1 according to claim 21, wherein the lower portion is a soft magnetic material having a saturation magnetic flux density of 0.5 to 1.5 T, and the upper portion is a soft magnetic material having a saturation magnetic flux density of 1.5 to 2.2 T. A method for manufacturing a magnetic head having a two-layer structure. 23. The method of manufacturing a magnetic head according to claim 22, wherein the ratio of the thickness of the upper part to the lower part of the lower magnetic core of the two-layer structure is from 1:10 to 1: 2. 24. A method of manufacturing a magnetic head according to claim 17, wherein said nonmagnetic metal gap layer is a laminate of a nonmagnetic high melting point metal and a nonmagnetic bonding metal. 25. A method of manufacturing a magnetic head according to claim 24, wherein said nonmagnetic metal gap layer has a thickness of 0.1 to 0.5 μm. 26. The non-magnetic high melting point metal according to claim 25, wherein
A method for manufacturing a magnetic head, comprising r, Ti, Ta, Nb, or an alloy thereof. 27. A method for manufacturing a magnetic head according to claim 25, wherein said magnetic bonding metal is Pd, Rh, Pt, or an alloy thereof. 28. The method of manufacturing a magnetic head according to claim 17, wherein said high Bs magnetic layer is a soft magnetic alloy having a saturation magnetic flux density of 1.5 to 2.0 T. 29. The high Bs magnetic layer according to claim 28, wherein
A method for manufacturing a magnetic head, comprising a Fe alloy, a Co-Ni-Fe alloy, or a soft magnetic alloy containing these elements and other elements. 30. The high Bs magnetic layer according to claim 28, wherein the track width is 0.2 to 2.0 μm and the thickness is 0.2 to 2.0 μm.
m, the method for manufacturing a magnetic head. 31. A magnetic disk drive on which the magnetic head according to claim 1 is mounted. 32. A magnetic disk drive equipped with the magnetic head according to claim 1 and having a recording density of 3 Gbit / square inch or more.