JPH10134315A - Floating magnetic head and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high density recording head by replacing the material of one side magnetic core half body in the vicinity of a floating surface with a non-magnetic material and providing a processing groove deciding a track width in the vicinity of the floating surface obliquely for the floating surface so as to become deep in the changed side magnetic core half body side. SOLUTION: A ferrite in the vicinity 17 of the floating surface of the magnetic core half body 10 of a magnetic core is removed and replaced with the non-magnetic material. Together with that, the processing groove 18 for deciding the track width is provided in the vicinity of the floating surface obliquely to the floating surface so as to be deeper in the replaced side magnetic core half body 10 side. Thus, the magnetic body value of the magnetic core half body 11 side is increased, and recording efficiency is enhanced. For instance, the angle between the processing groove 18 and the floating surface is regulated to 23 deg., and the depth (depth of step) Sd of the processing groove 18 measured from a gap depth position along a gap surface is regulated to 8μm. In such a manner, by providing the processing groove obliquely to the floating surface, a nonlinear magnetization transition point shift NLTS is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flying magnetic head, and more particularly, to the structure and manufacturing of a flying magnetic head suitable for high-density recording, having a small nonlinear magnetization transition point shift when used for high-density digital recording. About the method.

[0002]

2. Description of the Related Art In recent years, the recording density of a magnetic recording apparatus has been remarkably improved.
The recording density is increasing at an annual rate of 60%. FIG.
1 shows the structure of a floating magnetic head used in a magnetic disk drive for a computer. The magnetic head 1 comprises a non-magnetic slider 2 and a magnetic core 3. The magnetic core 3 is molded with glass or the like into a slit 6 formed in the floating surface 4 of the two floating surfaces 4, 5 of the slider 2. Fixed. FIG. 11 shows a detailed structure of the magnetic core 3. In FIG. 11A, a metal magnetic film 12 is formed on a surface facing a magnetic gap of a magnetic core half 10 made of an oxide magnetic material and on a slope of a magnetic core half 11 made of an oxide magnetic material. . The pair of magnetic core halves 10 and 11 are joined by a glass 14 via a magnetic gap material so as to have a magnetic gap 13. The winding window 15
, A predetermined winding is wound on the magnetic core half 10 side, but is omitted in this figure to avoid complication. On the air bearing surface side, a processing groove 16 for determining the track width Tw is formed in parallel with the air bearing surface to cope with the narrow track width. The recording / reproducing operation of the flying magnetic head uses the electromagnetic induction phenomenon, and generates a magnetic field for recording in the magnetic gap while maintaining a non-contact state with a very narrow gap with the medium. Is recorded by magnetic recording, or leakage magnetic flux from a medium is taken in and converted into an electric signal for reproduction.

[0003]

SUMMARY OF THE INVENTION In a magnetic disk drive for a computer, a non-linear magnetization transition point shift (Non Linear Transition Shift;
The problem is called NLTS for short).
Improvement of NLTS is an issue for realizing future increase in recording density. The NLTS is a phenomenon in which a recorded signal is deviated from a position to be originally recorded in recording a digital signal. This phenomenon is particularly caused by a metal-in-gap head (hereinafter abbreviated as MG head) formed by attaching a metal magnetic film near the magnetic gap of a core using an oxide magnetic material as described above. Frequently occurring in a floating magnetic head using a core, this has been a bottleneck when using this MG head for high density recording. An object of the present invention is to improve the NLTS in a flying magnetic head using an MG head core and provide a high-density recording head.

[0004]

According to the present invention, there is provided the above-mentioned NLTS.
This is a technical idea born from detailed examination of a conventional MG head in order to improve the above. The concept is to optimize the magnetic field distribution pattern in the vicinity of the magnetic gap. The gist of the concept is that the magnetic gap portion is configured so as to reverse conventional wisdom. Hereinafter, specific means will be referred to with reference to FIGS. 1) The main magnetic circuit of the two magnetic core halves is made of an oxide magnetic material, and a metal magnetic film is formed at least in the vicinity of the magnetic gap of the magnetic core halves. In a flying magnetic head using a magnetic core in which magnetic bodies are joined via a magnetic gap, an oxide magnetic material in the vicinity of the air bearing surface of at least one of the magnetic core halves is replaced with a non-magnetic material and provided near the air bearing surface. A machining groove for determining the track width is provided to be inclined with respect to the air bearing surface so as to be deeper on the side of the magnetic core half where the oxide magnetic material is replaced with a non-magnetic material. 2) In the flying magnetic head of 1), the surface of the magnetic film of the magnetic core half on which the oxide magnetic material is replaced with a non-magnetic material is substantially perpendicular to the floating surface at least in the vicinity of the magnetic gap. Deploy. 3) In the magnetic head of 1) or 2), the magnetic core half on the side where the oxide magnetic material is replaced with a non-magnetic material is arranged on the trailing side. 4) In the magnetic head of 1) to 3), the interface between the non-magnetic material and the oxide magnetic material in the magnetic core half on the side where the above-described oxide magnetic material is replaced with a non-magnetic material is located above the air bearing surface from the gap depth position. The distance between the interface and the position of the gap depth is 0 μm or more and 36 μm or less. 5) In the magnetic head of 1) to 3), the depth of the machining groove for determining the track width provided in the vicinity of the air bearing surface is measured from the gap depth position along the gap in a direction away from the air bearing surface. , 20 μm or less. 6) In the magnetic head of 1) to 3), the interface between the nonmagnetic material and the oxide magnetic material in the magnetic core half on the side where the oxide magnetic material is replaced with a nonmagnetic material is 0 μm or more from the gap depth position. It is 36 μm or less, and the depth of the processing groove for determining the track width provided near the air bearing surface is 20 μm or less. 7) In the magnetic head according to 4) or 6), the interface between the nonmagnetic material and the oxide magnetic material in the magnetic core half on the side where the oxide magnetic material is replaced with a nonmagnetic material is at least 2 μm from the gap depth position. It is 16 μm or less. 8) In the magnetic head of 5) or 6), the depth of the processing groove for determining the track width provided near the air bearing surface is set to 15 μm or less. 9) In the magnetic head of 6), the interface between the nonmagnetic material and the oxide magnetic material in the half of the magnetic core on the side where the oxide magnetic material is replaced with the nonmagnetic material is positioned at a distance of 2 from the gap depth position.
μm or more and 16 μm or less, and the depth of the processing groove for determining the track width provided near the air bearing surface is set to 15 μm.
m or less. 10) In the magnetic head of 1) to 9), a processing groove for determining a track width provided near the air bearing surface is formed by:
Provided only on one side of the magnetic core. 11) In the magnetic head of 1) to 9), a processing groove for determining a track width provided near the air bearing surface is formed by:
Provided on both sides of the magnetic core. 12) Also, in manufacturing the magnetic head of 1) to 11), a bonding block in which the two magnetic core half blocks to be the magnetic core half are joined with glass is manufactured, and then one of the magnetic cores is manufactured. By removing the ferrite (oxide magnetic material) near the air bearing surface of the half block by machining, and then cutting the chip,
A magnetic head core is manufactured.

In the magnetic head of the present invention, as described in the above 1), the oxide magnetic material near the air bearing surface is replaced with a non-magnetic material, and the processing grooves for determining the track width are provided at an angle. The NLTS is reduced by steepening the gradient of the recording magnetic field, the NLTS is prevented from increasing due to the recording current, and the magnetic volume of the magnetic core half is increased to increase the recording efficiency. This increases the change speed of the recording magnetic field and increases the NLTS
Decrease.

In the magnetic head of the present invention, the surface of the metal magnetic film of the half of the magnetic core on the side of replacing the oxide magnetic material near the air bearing surface with a nonmagnetic material is inclined with respect to the air bearing surface near the magnetic gap. Although it is possible to adopt the configuration described above, it is preferable to adopt a configuration in which the film surface of the metal magnetic film is substantially perpendicular to the air bearing surface in the vicinity of the magnetic gap as described in 2) above. This makes it easy to manufacture a magnetic core in which the oxide magnetic material is replaced with a non-magnetic material near the air bearing surface.

In the magnetic head of the present invention, the magnetic core half on the side where the oxide magnetic material in the vicinity of the air bearing surface is replaced with a non-magnetic material can be used as the inflow end (leading end) of the medium. Is the outflow end (trailing end) of the medium as in 3) above. Thereby, the core cross-sectional area on the side on which the winding is wound can be reduced, and the inductance can be reduced.

In the magnetic head of the present invention, the above 4)
As described above, the interface between the oxide magnetic material and the nonmagnetic material is set to 0 μm or more and 36 μm or less. More preferably, as described in 7) above, the thickness is 2 μm or more and 16 μm or less. This allows
The NLTS is reduced by preventing the magnetic field gradient from lowering, and the reproduction efficiency is also prevented from lowering. Also, as in 5) above,
The depth of the processing groove for determining the track width provided in the vicinity of the air bearing surface, measured in the direction away from the air bearing surface along the gap from the position of the gap depth, is set to 20 μm or less. More preferably, as described in 8) above, the thickness is 15 μm or less. Thereby, NLTS can be further reduced.

Further, as described in 6) above, the interface between the non-magnetic material and the oxide magnetic material is 0 μm from the gap depth position.
m or more and 36 μm or less, and the depth of the processing groove for determining the track width provided near the air bearing surface is set to 20 μm.
The following is assumed. More preferably, as described in 9) above, the interface between the non-magnetic material and the oxide magnetic material is set to 2 μm or more and 16 μm or less from the position of the gap depth, and the track width provided near the air bearing surface is determined. Is set to 15 μm or less. Thus, it is possible to maintain a high reproduction output, greatly reduce the NLTS, and prevent an increase in the NLTS due to the recording current.

In the magnetic head of the present invention, as in the above 10) and 11), the processing grooves for determining the track width can be provided on one side and both sides of the magnetic core. However, it is preferable to provide it on one side for improving productivity.

In producing the magnetic head of the present invention,
The magnetic core half block to be the magnetic core half is bonded with glass to form a bonding block, and after that, ferrite near the air bearing surface of one magnetic core half block is removed by machining, and then the chip is cut. As a result, a magnetic head core is manufactured. Thus, the magnetic head of the present invention can be manufactured with high productivity.

In the present invention, as the oxide magnetic material,
Mn-Zn single crystal ferrite is preferred. The composition is MnO
26 to 32 mol%, ZnO 14 to 21 mol%, and the balance Fe2O3. As the metal magnetic film, a magnetic film having a high saturation magnetic flux density containing Fe, Co, or Ni as a main component is used. Specifically, Fe-Si, Fe-N, Fe-Al-Si, Fe-Ga
-Si or other crystalline magnetic film, or Co-Nb-Zr, Co-Ta-Z
r, Co-W-Zr, Co-Fe-Si-B and other Co-based amorphous magnetic films. Also, a microcrystalline precipitation type magnetic film of Fe-Ta-N system, Fe-Ta-C system, etc. is excellent in saturation magnetic flux density and soft magnetic characteristics, and is particularly preferable. These metal magnetic films are formed on a core of an oxide magnetic material by a thin film forming method such as a sputtering method.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments. FIG. 12 shows NLTS and overwrite characteristics with respect to the recording current of the conventional magnetic head shown in FIG. MnZn ferrite single crystal was used as the oxide magnetic material, and FeTaNCr microcrystalline film was used as the metal magnetic film. The metal magnetic film was formed on a ferrite core by sputtering using a FeTaCr target in a mixed gas atmosphere of Ar-N2 using a magnetron sputtering apparatus. The saturation magnetic flux density of this metal magnetic film is 1.5T. The thickness of the magnetic film on the magnetic core half 10 was 2 μm, and the thickness of the magnetic film on the magnetic core half 11 was 5 μm. The depth (step depth) Sd from the gap depth position of the processing groove 16 for determining the track width was 8 μm, and the gap depth Gd was 1.5 μm. Measurement conditions were as follows: 26 turns, linear recording density of 12
0kFCI, frequency 56MHz, medium coercive force 2000Oe, flying height 25
nm. As shown in the figure, the overwrite shows a so-called roll-off characteristic that increases with an increase in the recording current and deteriorates after reaching the saturation value. Overwrite is less than -28 dB, preferably-
It must be 30 dB or less. Therefore, a recording current of about 10 mA is suitable. Near the used recording current
The NLTS was about 60% under the present measurement conditions, indicating an unsatisfactory large NLTS for the NLTS of 30% or less required for the operation of the magnetic disk drive.

To investigate the cause, the magnetic field strength and the magnetic field gradient were calculated by a magnetic field calculation simulation.
The result is shown in FIG. As shown in the figure, the magnetic field strength Hx in the medium running direction monotonically increases together with the magnetomotive force. On the other hand, the magnetic field gradient at a coercive force of 2000 Oe of the medium once increases and then largely decreases with the magnetomotive force. Overwrite and NL
TS is related to the magnetic field gradient, and it is said that as the magnetic field gradient decreases, overwrite deteriorates and NLTS increases. Therefore, it is considered that the overwrite degradation and the increase in NLTS due to the increase in the recording current shown in FIG. 12 are due to such a decrease in the magnetic field gradient. Such a decrease in the magnetic field gradient is caused by the magnetic gap 13 in the magnetic core shown in FIG.
It is considered that excessive magnetic flux was concentrated on the metal magnetic film near the area, causing magnetic saturation.

The present phenomenon was studied in more detail. The magnetic core (conventional example 1) of FIG.
Is a conventional magnetic core of another shape (conventional example 2) in which the ferrite in the vicinity 17 of the air bearing surface 4 on the magnetic core half 10 side of the conventional magnetic core shown in FIG. Here, the display of the non-magnetic material is omitted. In order to improve the reduction of the magnetic field gradient of the magnetic core of the above-mentioned conventional example 1, FIG.
The magnetic field gradient was calculated for the magnetic core of Conventional Example 2 shown in FIG. The distance from the interface between the ferrite and the non-magnetic material to the gap depth (ferrite notch position) fd is 5
μm. Other shapes were the same as the magnetic core of the first conventional example in FIG. FIG. 9 shows the result. In FIG. 9, it can be seen that the magnetic core shape of Conventional Example 2 shown in FIG. 11B maintains a high magnetic field gradient up to a high magnetomotive force. The magnetic core of Conventional Example 2 shown in FIG. 11B was manufactured, and overwrite and NLTS were evaluated.
The ferrite notch position fd was 5 μm. Other conditions are the same as those of the conventional magnetic core. The results are shown in FIG. As shown, the magnetic core half 1 of the magnetic core of the conventional example 1
The magnetic core of Conventional Example 2 in which the ferrite in the vicinity 17 of the air bearing surface 4 on the 0 side was removed and replaced with a non-magnetic material did not deteriorate even if the overwrite increased the recording current, and the roll seen in the conventional core No off characteristic occurs. Also, it was found that the NLTS did not increase with an increase in the recording current, and that the NLTS could be reduced by about 10 points at a recording current of 10 mA as compared with the magnetic core of Conventional Example 1. However, the degree of improvement was limited. FIG. 1 shows the structure of a magnetic core used in the magnetic head of the present invention. In the present magnetic core, a processing groove 18 for determining a track width is formed obliquely with respect to the air bearing surface 4.
As a result, the volume of the magnetic material on the side of the magnetic core half 11 is increased, and the recording efficiency is increased. The angle θ between the processing groove and the air bearing surface is 23 °, and the depth (step depth) Sd of the processing groove measured along the gap surface from the gap depth position
Was set to 8 μm. Other conditions are the same as the measurement conditions of the conventional magnetic core. FIG. 2 shows the measured values of NLTS of this magnetic core in comparison with other magnetic cores. As shown, NLTS is about 3
0%, and the change due to the recording current is small. As described above, it has been clarified that NLTS can be greatly improved by using the magnetic core of the present invention.

A magnetic field gradient was calculated for the head shown in FIG. 1 in order to examine the effect of the depth fd of the ferrite notch on the magnetic core half 10 side. The results are shown in FIG. As shown in the figure, when the ferrite notch position fd measured from the gap depth position is used as a parameter, fd = 0
At (ferrite notch position = gap depth position), the magnetic field gradient is improved as compared with the conventional magnetic core, and the effect of improving the magnetic field gradient can be clearly obtained by setting fd to 2 μm or more. In order to examine the effect of the depth fd of the ferrite notch on the reproduction characteristics, an equivalent magnet equivalent to the medium is placed at the tip of the gap of the magnetic core, and the magnetic flux flowing into the magnetic core and interlinking with the coil is set. Was calculated. In addition,
The relative permeability of ferrite is 200, and the relative permeability of metal magnetic film is 8
00 was set. As shown in FIG. 4, when fd is too large, the reproduction efficiency is reduced. 10% reduction in regeneration efficiency
In order to keep fd below, fd should be 36 μm or less and 5%
In order to achieve the following, fd needs to be 16 μm or less. Next, with respect to the head shown in FIG. 1, a head having a different step depth Sd was manufactured, and a change in NLTS was examined. FIG. 5 shows the results. As shown in the figure, the step depth is 20 μm
In the case described above, the NLTS becomes 50% or more, and the effect of inclining the groove for determining the track width is lost. Also, NLTS
Is set to be 40% or less, the step depth Sd is set to 15 μm.
m or less.

In practicing the present invention, several examples can be shown as a method of manufacturing a magnetic core in which the ferrite near the air bearing surface is replaced with a non-magnetic material. For example, there is a method in which a substrate in which a ferrite and a non-magnetic material are bonded in advance is prepared, a magnetic film is applied to the substrate, and then the glass is bonded. On the other hand, the present inventors have found a method capable of manufacturing the magnetic head of the present invention with high productivity. FIG. 7 shows an example of a method for manufacturing a magnetic head according to the present invention. Fig. 7 (a) and (b)
In the above, a ferrite block having grooves 19 and 19 ′ is prepared, and a metal magnetic film 12 is attached by sputtering to form a magnetic core half block 20 to be the magnetic core half 10 and a magnetic core half 11. The magnetic core half block 21 is manufactured. Next, in FIG. 3C, the unnecessary metal magnetic film on the magnetic gap surface 22 of the magnetic core half block 21 is removed, and mirror polishing is performed. Further, a magnetic gap surface 22 ′ of the magnetic core half block 21 and
An SiO2 film serving as a magnetic gap material is applied to the magnetic gap surface 22 of the magnetic core half block 20 to a predetermined thickness. Next, in FIG. 4D, the magnetic core half blocks 20 and 21 are joined using the glass 14 to form a bonding block 23. Next, in (e), the ferrite in the vicinity of the air bearing surface of the magnetic core half block 20 to be the magnetic core half 10 is removed by machining, leaving the metal magnetic film, to form a ferrite removed portion 17. Next, the portion indicated by the broken line is cut in (e) to obtain the magnetic core shown in (f). Further, the track width determining groove 18 is processed to manufacture a magnetic core used in the magnetic head of the present invention.

As described above, in the manufacturing method of the present invention, a bonding block in which the magnetic core half blocks are bonded with glass is manufactured, and thereafter, the ferrite near the floating surface of one magnetic core half block is machined. Delete
By performing chip cutting after that, the magnetic core of the present invention can be manufactured with high productivity. The portion from which the ferrite has been removed is filled with glass in the step of embedding the magnetic core in the slider. As described above, when a substrate in which a nonmagnetic material and ferrite are joined is used, the magnetic core halves to be replaced with the nonmagnetic material are the magnetic core halves 10 and 11.
In the method of removing the ferrite near the air bearing surface of the bonding block by machining, the ferrite can be removed only when the film surface of the metal magnetic film is almost perpendicular to the air bearing surface near the gap. Core half 1
Only on the 0 side. Therefore, in the magnetic head of the present invention,
In a more preferred embodiment, the ferrite near the air bearing surface of the magnetic core half 10 in which the film surface of the magnetic film is substantially perpendicular to the air bearing surface near the gap is replaced with a non-magnetic material.

In the magnetic core of the present invention shown in FIG. 1, the inclined processing groove 18 for determining the track width is formed only on one surface of the magnetic core. It is clear from the above description that the effect of the present invention is not limited to the configuration of FIG. That is, FIG. 6 shows the shape of the magnetic core of the present invention viewed from the air bearing surface. FIG. 6A shows a case where the processing groove 18 is formed only on one side of the magnetic core, and FIG. 6B shows a case where the processing groove 18 is formed on both side surfaces of the magnetic core. The effect of the present invention can be similarly obtained when the processing grooves are provided on both side surfaces of the magnetic core as in (b). However, from the viewpoint of productivity, the processing groove 18 is formed only on one side.
(B) is advantageous.

[0020]

As will be apparent from the above description, in the case of a flying magnetic head using a magnetic core formed by applying a metal magnetic film having a high saturation magnetic flux density to a half of a magnetic core made of ferrite, By removing the ferrite near the air bearing surface on the side and performing step processing to form the track width at an angle to the air bearing surface, NLTS can be significantly reduced, and at the same time, high recording density and high transfer speed can be achieved. It is possible to provide a floating magnetic head suitable for a small magnetic disk drive to be used.

[Brief description of the drawings]

FIG. 1 is a perspective view of a magnetic core showing one embodiment of the present invention;

FIG. 2 shows NLTS characteristics of a magnetic core of the present invention,

FIG. 3 shows a relationship between a notch position fd of a magnetic core and a magnetic field gradient according to the present invention;

FIG. 4 shows a relationship between a notch position fd of a magnetic core according to the present invention and a reproducing magnetic flux,

FIG. 5 is a view showing NLTS of the magnetic core of the present invention;

FIG. 6 is a plan view from the air bearing surface of a magnetic core showing another embodiment according to the present invention;

FIG. 7 shows an example of a method for manufacturing a magnetic core according to the present invention,

FIG. 8 is a perspective view of a conventional floating magnetic head,

FIG. 9 shows magnetomotive force versus magnetic field gradient characteristics of a conventional magnetic core,

FIG. 10 shows a conventional magnetic core overwrite and NL.
TS characteristics,

FIG. 11 is a perspective view of a conventional magnetic core,

FIG. 12 shows a conventional magnetic core overwrite and NLTS.
Characteristic,

FIG. 13 shows the relationship between the magnetic field strength and the magnetic field gradient of a conventional magnetic core.

[Explanation of symbols]

Reference Signs List 1 magnetic head, 2 slider, 3 magnetic head core, 4,5 air bearing surface, 6 slit, 10,11 magnetic core half, 12 metal magnetic film, 13 magnetic gap, 14
Glass, 15 winding window, 16, 18 Track width determining groove, 17 Ferrite removal part, 19, 19 'groove,
20, 21 magnetic core half block, 22, 22 'magnetic gap surface, 23 bonding block

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigekazu Suwabe 5200 Sankajiri, Kumagaya-shi, Saitama Hitachi Metals Co., Ltd. Magnetic Materials Research Laboratories (72) Inventor Keiichi Kondo 6010 Mitsugajiri, Kumagaya-shi, Saitama Prefecture Production Systems Research Laboratory, Hitachi Metals, Ltd.

Claims (13)

[Claims] 1. Two magnetic core halves made of an oxide magnetic material are joined by glass so as to form a magnetic gap,
At least one of the magnetic core halves having a metal magnetic film disposed in the vicinity of the magnetic gap and having a processing groove for regulating a track width is provided with a magnetic core exposed and fixed to a flying surface side of a slider. In the type magnetic head, at least one of the magnetic core halves removes or replaces the oxide magnetic material near the air bearing surface of the magnetic core half, and replaces or removes the oxide magnetic material. A floating magnetic head characterized in that the processing groove is provided to be inclined with respect to the air bearing surface so as to be deeper on the side of the magnetic core half replaced with a magnetic material. 2. The floating magnetic head according to claim 1, wherein the metal magnetic film surface of the magnetic core half in which the oxide magnetic material has been removed or replaced with a non-magnetic material is at least in the vicinity of a magnetic gap. A flying magnetic head characterized by being disposed substantially at right angles to the air bearing surface. 3. The floating magnetic head according to claim 1, wherein the half of the magnetic core from which the oxide magnetic material has been removed or replaced with a non-magnetic material is disposed on the trailing side. A floating magnetic head characterized in that it is configured as described above. 4. The floating magnetic head according to claim 1, wherein said oxide magnetic material is removed or replaced with a nonmagnetic material. A floating magnetic head, wherein a material interface is arranged so as to be further away from a floating surface than a gap depth position, and a distance between the interface and the gap depth position is 0 μm or more and 36 μm or less. 5. The flying magnetic head according to claim 1, wherein the depth of the machining groove is measured to be 20 μm from the position of the gap depth along the magnetic gap in a direction away from the air bearing surface. A floating magnetic head characterized by the following. 6. The floating magnetic head according to claim 1, wherein the nonmagnetic material and the oxide magnetic material in the half of the magnetic core on the side where the oxide magnetic material is replaced with a nonmagnetic material. The interface is 0 μm or more from the position of the gap depth,
A floating magnetic head having a thickness of 36 μm or less and a depth of the processing groove of 20 μm or less. 7. The floating magnetic head according to claim 4, wherein said oxide magnetic material is removed or replaced with a non-magnetic material. A floating magnetic head, wherein an interface of a material is set to 2 μm or more and 16 μm or less from a position of a gap depth. 8. The flying magnetic head according to claim 5, wherein the depth of the processing groove is 15 μm.
A floating magnetic head characterized by having a diameter of less than m. 9. The floating magnetic head according to claim 6, wherein the interface between the nonmagnetic material and the oxide magnetic material in the half of the magnetic core on which the oxide magnetic material has been removed or replaced with a nonmagnetic material. 2 to 16 μm from gap depth position
And a depth of the processing groove is set to 15 μm or less. 10. The floating magnetic head according to claim 1, wherein said machining groove is provided on only one surface of said magnetic core. 11. The floating magnetic head according to claim 1, wherein said machining grooves are provided on both side surfaces of said magnetic core. 12. The two magnetic core halves made of an oxide magnetic material are joined by glass so as to form a magnetic gap, and a metal magnetic film is arranged at least in the vicinity of the magnetic gap among the magnetic core halves. And a magnetic core provided with a processing groove for regulating a track width, wherein at least one of the magnetic core halves is a magnetic core half. The oxide magnetic material in the vicinity of the air bearing surface is removed or replaced with a non-magnetic material, and the processed groove is raised so as to be deeper on the side of the magnetic core half where the oxide magnetic material has been removed or replaced with the non-magnetic material. A floating magnetic head characterized in that a non-linear magnetization transition point shift (NLTS) is reduced by being provided to be inclined with respect to a plane. 13. The two magnetic core halves made of an oxide magnetic material are joined by glass so as to form a magnetic gap, and a metal magnetic film is arranged at least in the vicinity of the magnetic gap among the magnetic core halves. And a magnetic core provided with a processing groove for regulating a track width, wherein the magnetic gap is exposed and fixed to the flying surface side of the slider. A step of producing a bonding block in which the magnetic core half blocks are bonded with glass, a step of removing the oxide magnetic material near the air bearing surface of one of the magnetic core half blocks by machining, and a step of cutting the chips. A method for manufacturing a flying magnetic head.