JPH103608A - Magnetic head and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the effect due to adjacent cross talk. SOLUTION: Track width control grooves 24a, 24b in nearly same shape and with different groove depths are formed alternately. Then, by positioning these track width control grooves 24a, 24b with different groove depths, deviation according to a difference between the track width control groves 24a, 24b is given to a confronting position between magnetic gap forming projecting parts 24A of respective magnetic core half bodies.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head suitable for mounting on a magnetic recording / reproducing apparatus capable of high-density recording, such as a video tape recorder (VTR) or a digital audio tape recorder (R-DAT), and its manufacture. About the method.

[0002]

2. Description of the Related Art For example, in order to perform high-density recording,
It is necessary to make the track pattern recorded on the magnetic recording medium as narrow as possible. As one method, recording without providing a guard band between tracks,
There is a so-called guard bandless recording method. In such a recording method, the recording density can be improved because there is no guard band.

However, in this guard bandless recording system, since there is no guard band between tracks, so-called adjacent crosstalk, which occurs when a magnetic head traces (reproduces) a signal of an adjacent track, poses a problem. Become.

[0004] This will be described with reference to a magnetic head mounted on a home VTR. As shown in FIG. 1, in this magnetic head, recording and reproduction are usually used for both purposes. To ensure this, the head width (gap width) HW of the reproducing head is formed wider than the recording track pitch.

Therefore, when a recording pattern having no guard band is reproduced by the magnetic head mounted on the home VTR, the recording track T adjacent to the track TA where the gap G1 in which the magnetic gap has shifted is found.
The signal of B is picked up, and the adjacent crosstalk occurs.

[0006]

By the way, in a conventional magnetic head, for example, in the case of a home digital VTR, when an azimuth-recorded signal is reproduced, even if the reproduction C / N is fixed, an error is obtained. There is a variation of about ± 1 digit in the rate, and a magnetic recording / reproducing apparatus such as a home digital VTR equipped with a magnetic head must be designed with a lower limit of the variation.

In a conventional magnetic head, for example, in a long-time recording in which the standard tape feed speed of a home VTR is set to 2/3 and the recording / reproduction time is increased by 1.5 times,
There was a problem that an error rate sufficient for reproduction could not be obtained due to insufficient C / N.

On the other hand, when the track pitch, which is the pitch of the pattern recorded on the magnetic tape, becomes narrower with the increase in the recording density, the influence of the adjacent crosstalk increases, and the S / N and the error rate are degraded. It is known that

For this reason, in the conventional magnetic head, in order to minimize the influence of adjacent crosstalk during reproduction, the angle of the track width regulating groove is formed so as to be substantially perpendicular to the surface facing the magnetic gap. Can be considered.

However, the magnetic head having such a shape has a small cross-sectional area of the magnetic core near the magnetic gap, which is not preferable in terms of recording and reproduction.

Further, a conventional method for manufacturing a magnetic head includes:
The projections for forming the magnetic gap of the pair of magnetic core halves are not completely aligned and butted to both ends, and the ends of the projections for forming the magnetic gap of the pair of magnetic core halves are displaced. It is known that adjacent crosstalk is caused by this shift, but the relationship between the shift and adjacent crosstalk is not specifically clarified.

For this reason, for example, by forming the track width regulating groove at a large angle, that is, by forming the track width regulating groove into a V-shaped groove having a large angle, both ends of the magnetic gap forming projections of the pair of magnetic core halves can be formed. As long as they match.

However, when the angle of the track width regulating groove is increased, the conventional magnetic head manufacturing method performs the work of abutting the magnetic gap only at the edge of the track width regulating groove. Had.

The present invention has been proposed in view of such a conventional technical problem, and provides a magnetic head capable of suppressing the influence of adjacent crosstalk. It is an object of the present invention to provide a method of manufacturing a magnetic head for manufacturing a magnetic head with a high processing yield.

[0015]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, the influence of adjacent crosstalk has been reduced by restricting the amount and direction of the track width of the magnetic gap. In addition to finding that the magnetic gap can be suppressed to a small value, the present inventors have found a method of manufacturing a magnetic head in which the deviation amount and the direction of the track width of the magnetic gap are constant.

That is, the present inventors obtained the experimental results shown in FIGS. 4 and 5, and studied the experimental results in detail, and completed the invention capable of realizing the operation and effect described later.

First, as a case where the magnetic gap is shifted, as shown in FIG. 3, the direction of the center line F caused by the shift of the ends of the magnetic gap forming projections of the pair of magnetic core halves is changed. A case where the direction becomes closer to the azimuth angle of the recording track TB adjacent to the desired recording track TA;
As shown in FIG. 2, the direction of the center line F generated by the displacement of the ends of the magnetic gap forming projections of the pair of magnetic core halves is the direction in which the azimuth angle of the recording track TA and the recording track TB adjacent to the recording track TA become farther Is divided into

That is, the relationship between the direction of the bisector F of the opening angle θ due to the displacement G1 of the magnetic gap g and the angle of azimuth recording of an adjacent recording track is considered.
The case of FIG. 2 is referred to as “a deviation of the magnetic gap in the + direction”, and the case of FIG. 3 is referred to as “a deviation of the magnetic gap in the − direction”.

In the portion G2 where the head width (gap width) HW of the reproducing head extends over the adjacent recording track TB, the track T determined by the regular magnetic gap is used.
The signal of A is picked up, and the signal of the adjacent recording track TB is not picked up for scanning the so-called reverse azimuth.

Therefore, when the influence of adjacent crosstalk in both cases is examined, it can be seen that the influence of adjacent crosstalk is small as shown in FIG. On the other hand, when the magnetic gap is shifted in the negative direction, as shown in FIG. 5, it can be seen that the influence of the adjacent crosstalk is large.

Here, FIGS. 4 and 5 are characteristic diagrams showing how the error rate changes due to adjacent crosstalk in the case where the magnetic gap is displaced. FIGS. 4 and 5 show the case where the azimuth angle of the magnetic head is ± 20 °. The plots (vertical lines) shown in FIGS. 4 and 5 are the results of measuring the influence of adjacent crosstalk with “present” and “absent”. It is a plot, and the upper part of the vertical line is a plot of a portion affected by crosstalk. One line indicates data of one magnetic head.

By the way, the adjacent pattern components picked up by the regular magnetic gap g can suppress the high frequency part due to the azimuth loss. Loss can hardly be expected. actually,
In a high frequency part, there is a case where it is about 5 dB higher than the amount picked up from the regular magnetic gap. Therefore, for example, in a system in which low-frequency components are not used for signal detection, such as a signal of a partial response class 4, such leakage from a relatively high frequency adjacent track has a considerable effect on signal detection. Will be.

From the above results, it is sufficient to manufacture the magnetic head so that the magnetic gap is shifted in the + direction or to manufacture the magnetic gap so that the magnetic gap is not shifted. According to the method, when the magnetic gap abutment operation is performed while the direction of the magnetic gap deviation is kept constant, it is difficult to control the amount of deviation of the magnetic gap in the track width direction, and it is not possible to maintain high track accuracy.

In order to solve the above-mentioned problems, a magnetic head according to the present invention includes a pair of magnetic core halves each having a track width regulating groove formed therein and a magnetic gap forming projection formed thereon. In a magnetic head having a magnetic gap having a predetermined azimuth angle between the butting surfaces of the magnetic gap forming projections, the shape of each of the track width regulating grooves is formed. Are substantially the same shape, and the positions of the inflection points in the groove shapes in the track width regulating grooves facing each other and the track width regulating grooves adjacent to each other are different from each other in the groove depth direction. It is characterized in that a deviation in the track width direction is given to the abutting position of the magnetic gap forming projection.

On the other hand, the method of manufacturing the magnetic head of the present invention
A pair of magnetic core halves, each having a track width regulating groove formed thereon and a magnetic gap forming protrusion formed thereon, are joined and integrated so that the track width regulating groove forming surfaces face each other, and the magnetic gap forming protrusion is formed. In a method of manufacturing a magnetic head for forming a magnetic gap having a predetermined azimuth angle between abutting surfaces of the magnetic heads, track width regulating grooves having substantially the same shape and different groove depths are alternately formed, and track widths having different groove depths are formed. By aligning the regulating grooves, a displacement corresponding to the difference in the groove depth of the track width regulating grooves is given to the abutting position of the magnetic gap forming protrusion of each magnetic core half.

The above deviation is caused by the fact that the angle formed by the center line between the butting surface of the magnetic gap forming projection and the wall surface of the track width regulating groove facing the magnetic recording medium and the azimuth direction of the adjacent recording track is the magnetic gap. And an azimuth direction between the adjacent recording tracks.

According to the method of manufacturing a magnetic head of the present invention,
The track width regulating grooves having substantially the same shape and different groove depths are alternately formed, and the track width regulating grooves having different groove depths are aligned, so that the magnetic gap forming protrusions of each magnetic core half abut. By providing a displacement corresponding to the difference in the groove depth of the track width regulating groove to the position, a high-precision butting in which the displacement of the magnetic gap in the track width direction is adjusted to be constant in only one direction is performed.

Here, the track width regulating grooves having different groove depths can be easily formed by controlling only the depth using a slicer or the like having the same shape.

The angle formed by the center line between the abutting surface of the magnetic gap forming projection and the wall surface of the track width regulating groove facing the azimuth direction and the azimuth direction of the adjacent recording track is the magnetic gap and the adjacent magnetic track. A magnetic head capable of suppressing crosstalk from an adjacent channel at the time of reproduction is manufactured by giving a deviation so as to be larger than an angle formed between the recording track and the azimuth direction.

In the magnetic head manufactured by such a manufacturing method, the track width regulating grooves have substantially the same shape, and the track width regulating grooves facing each other and the track width regulating grooves adjacent to each other have the same groove shape. The position of the inflection point is different in the groove depth direction, and a deviation in the track width direction is given to the abutting position of the magnetic gap forming protrusion of each magnetic core half. When reproducing, crosstalk from an adjacent channel can be suppressed.

[0031]

Embodiments of the present invention will be described below in detail with reference to the drawings.

In the present embodiment, a metal-in-gap (Metal in Gap) type magnetic head (hereinafter, referred to as a magnetic head) in which a magnetic gap portion is formed by a metal magnetic film.
It is called “MIG head”. ).

As shown in FIG. 6, the magnetic head of this embodiment has
A closed magnetic path is formed by a pair of magnetic core halves 5 and 6 including ferrite magnetic core substrates 1 and 2 and metal magnetic films 3 and 4 respectively formed on butted surfaces of the magnetic core substrates 1 and 2. A magnetic gap g provided with an azimuth angle is formed between the butting surfaces of the metal magnetic films 3 and 4 and operates as a recording / reproducing gap.

The magnetic core substrates 1 and 2 are made of an oxide magnetic material such as ferrite, for example, and function as auxiliary cores for backing up the metal magnetic films 3 and 4 having a small core cross-sectional area and functioning as a main core. ing. That is, since the core cross-sectional area of the metal magnetic films 3 and 4 is small, deterioration of the reproduction output is prevented by the core volumes of the magnetic core substrates 1 and 2.

In each of the magnetic core substrates 1 and 2, the shape of the abutting surface is formed to have a substantially trapezoidal cross section. That is, the abutting surfaces of the magnetic core substrates 1 and 2 have the gap forming surfaces 7 and 8 parallel to the magnetic gap g and the track width Tw of the magnetic gap g at both ends of the gap forming surfaces 7 and 8. Track width regulating grooves 9, 10, 11, 12 for regulating are formed.

The track width regulating grooves 7, 8, 9,
A non-magnetic material 14 such as glass is filled in each of the layers 10 for the purpose of securing the contact characteristics with the magnetic recording medium and preventing uneven wear due to sliding contact.

The depth of the magnetic gap g is restricted on the butted surface of one magnetic core substrate 1.
A winding groove 13 having a substantially U-shaped cross section for winding a coil (not shown) is formed in the core thickness direction.

On the other hand, the metal magnetic films 3 and 4 are formed on the butting surfaces of the magnetic core substrates 1 and 2 from the front side to the back side. That is, the metal magnetic film 3,
Reference numerals 4 denote gap forming surfaces 7 and 8 of the magnetic core substrates 1 and 2 and track width regulating grooves 9 and 10 provided on both end sides thereof.
It is formed on 11 and 12 from the front side to the back side.

For the metal magnetic films 3 and 4, a ferromagnetic material having a high saturation magnetic flux density and excellent soft magnetic properties is used. , Non-crystalline or microcrystalline ones can be used.

For example, Fe-Al-Si alloy (Sendust), Fe-Si-Co alloy, Fe-Ni
Alloy, Fe-Al-Ge alloy, Fe-Ga-Ge alloy, Fe-Si-Ge alloy, Fe-Si-Ga alloy, Fe-Si-Ga-Ru alloy, Fe-Co-Si
-Al alloys and the like. In order to further improve corrosion resistance, wear resistance, etc., Ti, Cr, Mn, Z
r, Nb, Mo, Ta, W, Ru, Os, Rh, Ir,
At least one of Re, Ni, Pd, Pt, Hf, V and the like may be added. Also, oxygen-containing sendust, nitrogen-containing sendust, oxygen-containing Fe—Si—Ga
A crystalline magnetic film such as a -Ru alloy or a nitrogen-containing Fe-Si-Ga-Ru alloy may be used. Further, an Fe-based microcrystalline film or a Co-based microcrystalline film may be used.

As a method for forming these metal magnetic films 3 and 4, any vacuum thin film forming technology represented by a vacuum deposition method, a sputtering method, an ion plating method, a cluster ion beam method, or the like is employed.

Further, the metallic magnetic films 3 and 4 may be an intermediate layer of the ferromagnetic alloy material, for example SiO _2, T
A stacked film may be formed by stacking any number of layers via an insulating film such as a ₂ O ₃ , ZrO ₂ , and Si ₃ NO ₄ .

In addition to the ferrite material, non-magnetic ferrite, zirconium oxide-based ceramic, crystallized glass, non-magnetic iron oxide-based ceramic, BaT
Titanate-based ceramics such as iO ₃ and K ₂ TiO ₃ are used.

In the magnetic head of the present embodiment, in particular, as shown in FIG. 2, a deviation G1 in the track width direction is applied to the butting position of the magnetic gap forming projections 24A of the magnetic core halves 5, 6. ing.

The deviation G1 is an angle formed by the center line F between the butting surface 8 of the magnetic gap forming projection 24A and the wall surface 10 of the track width regulating groove facing the same and the azimuth direction of the adjacent recording track TB. θ2 is a deviation in a direction that is larger than an angle θ formed between the magnetic gap g and the azimuth direction of the adjacent recording track TB (the above-mentioned “displacement of the magnetic gap in the positive direction”).

This is because, as shown in FIG. 4, the amount of the adjacent pattern signal picked up by the gap G1 of the magnetic gap strongly depends on the direction of the gap G1 of the magnetic gap. That is, the track width regulating groove 1 for regulating the track width Tw.
By forming the direction of the bisector F of the opening angle θ due to the deviation G1 of the magnetic gap g of 0, 11 away from the azimuth recording angle of the adjacent recording track, the azimuth recording of the adjacent recording track is performed. This is because there is no influence, and crosstalk from adjacent channels can be reduced.

Therefore, in the present embodiment, the track width T
The direction of the bisector F of the opening angle θ due to the deviation G1 of the magnetic gap g of the track width regulating grooves 10 and 11 for regulating w is formed in a direction away from the azimuth recording angle of the adjacent recording track.

Further, the pair of magnetic core halves 5, 6 configured as described above abut the metal magnetic films 3, 4 formed on the gap forming surfaces 7, 8 while aligning tracks. The opposite portions of the first inclined surfaces 9 and 10 and the second inclined surfaces 11 and 12 formed at both end edges of the magnetic gap g are bonded and integrated by filling the fused glass 14 with the metallic magnet. Magnetic gap g between films 3 and 4
The track width Tw is 1 for the purpose of high-density magnetic recording.
It is less than 3 microns. In addition, the fusion glass 14 filled in the opposing portions of the first inclined surfaces 9 and 10 and the second inclined surfaces 11 and 12 is designed to ensure contact with the magnetic recording medium.

In particular, as shown in FIG. 18, each of the track width regulating grooves 7, 8, 9, 10, 11, 12 has substantially the same shape, and the track width regulating grooves opposing each other and adjacent to each other. In the track width regulating groove, the positions of the inflection points O1 and O2 in the groove shape are different from each other in the groove depth direction.

That is, the perpendicular line M1 of the gap forming surfaces 7, 8 near the first inclined surfaces 9, 10 of the track width regulating groove has a length L up to a position Z1 corresponding to the bottom surface of the track width regulating groove.
1 and a length L2 from the perpendicular M2 of the gap forming surfaces 7, 8 near the second inclined surfaces 11, 12 to a position Z2 corresponding to the bottom surface of the track width regulating groove is different.
1 <L2). This is to make it possible to adjust the amount of deviation δ of the magnetic gap in the width direction to be constant by an easy manufacturing method when manufacturing by a manufacturing method described later.

In this embodiment, these perpendiculars M1 and M2
The difference d between the lengths L1 and L2 is 1.3 μm.
In the present invention, the difference d is not limited to the one according to the present embodiment as long as the difference d is 0.5 to 3.0 μm.

This value is determined by the length L1 to the position Z1 where the perpendicular M1 of the gap forming surfaces 7, 8 near the first inclined surfaces 9, 10 corresponds to the bottom surface of the track width regulating groove, and the second inclined surface. The perpendicular line M2 of the gap forming surfaces 7, 8 near 11 and 12 has a length L up to a position Z2 corresponding to the bottom surface of the track width regulating groove.
2, the angle between the first inclined surfaces 9, 10 and the perpendiculars of the gap forming surfaces 7, 8 is θ2, and the second inclined surface 11,
12 and the angle between the perpendiculars of the gap forming surfaces 7 and 8 are θ
3. Assuming that the amount of deviation of the magnetic gap in the width direction is δ, it can be obtained by the equation d = δ / (tan θ2 + tan θ3).

By the way, the groove shape of the track width regulating groove is as follows.
It depends on the type of magnetic head. For example, there are magnetic heads as shown in FIGS. 19 and 20. In these cases,
As shown in FIGS. 19 and 20, the length L1 of the first inclined surfaces 9 and 10 and the length L of the second inclined surfaces 11 and 12 are determined.
2 is the length to the inflection points O1 and O2, respectively. In the drawing, reference numeral S1 indicates a sliding surface of the magnetic recording medium, and S2
Indicates a hit width processed portion.

Next, a method for manufacturing the magnetic head of this embodiment will be described.

First, as shown in FIG. 7, a substrate 21 made of a ferrite material is prepared. Then, the surface of the substrate 21 is set using a surface grinder.

In this example, the substrate 21 is a single crystal or polycrystal of a magnetic ferrite material, a bonding material thereof, or a nonmagnetic ferrite, BaTiO ₃ , K ₂ TiO ₃ ,
Non-magnetic materials such as crystallized glass can be used.

The plane orientation of the single crystal ferrite used in the present embodiment is as shown in FIG. 7. However, single crystal substrates and polycrystal substrates having other plane orientations, and single crystal ferrite and polycrystal ferrite are used. May be used.

Next, as shown in FIG. 8, a winding groove 22 and a glass groove 2 are formed in the longitudinal direction of the substrate 21 by using a slicer.
3 are formed two by two. That is, the winding groove 22 and the glass groove 23 are formed symmetrically from the center of the substrate 21. By forming in this manner, a pair of magnetic core blocks 21a and 21b to be a pair of magnetic core halves are formed from the one substrate 21.

Next, as shown in FIG. 9, a track width regulating groove 24 is formed in a direction perpendicular to the winding groove 22 and the glass groove 23, that is, in the width direction of the substrate 21, using a slicer. After the formation of the track width regulating grooves 24, the surface of the substrate 21 is mirror-finished by polishing or the like.

In forming the track width regulating groove 24, the groove depth (d) is different and the opening width W is different.
1 and W2 alternately form track width regulating grooves 24a and 24b.

In the present embodiment, as shown in FIG.
The wide opening width W1 is 201.5 μm, and the narrow opening width W2 is 200 μm. The width H1 of the magnetic gap forming protrusion 24A is 13 μm, and the difference d between the groove depths of the adjacent track width regulating grooves 24a and 24b is 1.
3 μm.

In this regard, when the conventional track width regulating groove is formed, the track width regulating groove is formed such that the distance from the gap opposing surface to the bottom surface is all uniform. Also, the track width regulating groove is 30
° and were formed to be all uniform.

However, the conventional method of manufacturing a magnetic head is as follows.
The end portions of the magnetic gap forming projections of the pair of magnetic core halves are displaced, and the dislocations are so-called pseudo gaps, causing the above-described problem of adjacent crosstalk.
For this reason, when forming the track width regulating groove on the substrate,
It is conceivable that a groove serving as a marker is formed in a part of the substrate, or a special process for abutting is performed. However, such a special process takes time or lowers productivity.

On the other hand, in the present embodiment, FIG.
As shown in FIG. 5, in order to adjust the amount of deviation δ in the width direction of the magnetic gap, the perpendicular M1 of the gap forming surfaces 7, 8 near the first inclined surfaces 9, 10 is formed on the bottom surface of the track width regulating groove 24. The length L1 to the corresponding position Z1 is different from the length L2 to the position Z2 where the perpendicular M2 of the gap forming surfaces 7, 8 near the second inclined surfaces 11, 12 corresponds to the bottom surface of the track width regulating groove 24. It is formed as follows. That is, the distances L1, L2 from the gap forming surfaces 7, 8 of the track width regulating grooves 24a, 24b to the groove bottom are formed to be different.

When such a track width regulating groove 24 is formed, a slicer having the same shape as the track width regulating groove 24 is used, and the slicer is formed by polishing the substrate 21 deeply or shallowly. I suffice. By forming in this manner, it is not necessary to perform a special process a plurality of times only for adjusting the displacement amount δ of the magnetic gap in the width direction, and it does not take much time for the process.

In this embodiment, the track width regulating groove 24 having a substantially trapezoidal shape is used, but the shape of the track width regulating groove 24 is, for example, as shown in FIGS. The track width regulating groove 24 may have another shape such as a V-shaped groove or having inflection points O1 and O2 in the groove.

Next, as shown in FIG.
1 is cut from the center thereof, and the cut substrates 21a, 2
1b is prepared.

In this embodiment, one substrate 2
In addition, since the track width regulating groove 24 is formed in addition to the winding groove 22 and the glass groove 23, the above-described cutting allows the groove depth (d) and the opening width W of every other one to be symmetrical.
Track width regulating grooves 24 having different widths 1 and W2 are formed.

Next, the cut substrates 21a, 21
12B, a metal magnetic film 27 is formed by sputtering, and a gap film 28 is formed thereon, as shown in FIGS. When forming the metal magnetic film 27, as shown in FIG. 13, the metal magnetic film 27 is formed including the inside of the track width regulating groove. In this embodiment, an Fe-Si-Ga-Ru alloy is used as the metal magnetic film 27.

Here, in order to improve the adhesion between the substrates 21a and 21b and the metal magnetic film 27, an oxide film such as SiO _2, Ta ₂ O ₅ , a nitride film such as Si ₃ O ₄ , or Cr,
A metal film of Al, Si, Pt or the like, an alloy film thereof, or a stacked film combining these may be used as a base film of the metal magnetic film 27. In the present embodiment, an SiO ₂ film having a thickness of 5 nm is used to improve the adhesive force.

Although a single-layer SiO ₂ film is used as the gap film, a two-layer film or a multilayer film having a Cr film or the like as an upper layer may be used as a film for preventing the reaction with the fused glass 11. good.

Next, the substrates 21a and 21b manufactured as described above are heated to 500 to 700 ° C. while being pressed, and are bonded with the low melting glass 14 as shown in FIG. Is prepared.

At the time of this joining, as shown in FIG. 15, butting was performed so that different track width regulating grooves 24a and 24b formed on the substrates 21a and 21b face each other.

Here, since the track width regulating grooves 24a, 24b having different groove depths and opening widths are formed in the respective substrates 21a, 21b, when the substrates 21a, 21b are abutted, the track width regulating grooves 24a, 24b are formed. By shifting the gap 24b by one and then performing the gap abutting so that there is no track shift alternately, the magnetic gap can be joined with high precision while generating a constant shift δ in the width direction. In this example, the displacement δ in the width direction of the magnetic gap is
As described above, it is 1.5 μm.

Next, after the bonding substrate 30 is made to have a predetermined thickness by using a flat surface removing plate, a portion to be a sliding surface of the magnetic recording medium is subjected to cylindrical grinding.

Next, in order to secure contact with the magnetic recording medium on the sliding surface of the magnetic recording medium, as shown in FIG.
After performing the contact width processing and the processing of the winding groove 22 and the like,
As shown in FIG. 17, a large number of head chips 31 are manufactured by cutting out at the same angle as the target azimuth angle.

In this cutting, the azimuth angle was made to be ± 20 °.
The azimuth angle was determined so that the magnetic gap in the direction was shifted. Thus, the magnetic head is completed as shown in FIG.

The deviation δ in the track width direction of the magnetic gap of the magnetic head manufactured as described above was measured.

As a result, when the gap abutting operation was performed in one direction only with the track width regulating groove of the conventional magnetic head, 3σ = 1.5 μm. The magnetic head has 3σ = 0.
A significant improvement of 7 μm was observed.

The magnetic head manufactured as described above is a high-precision magnetic head capable of improving the error rate of a reproduced signal. Therefore, a home digital VTR
According to this method, a sufficient error rate can be obtained even during long-time recording, and it is expected that a Viterbi multifunction device, which is a circuit for improving the error rate by storing past determination conditions, is not required.

Although the specific embodiments to which the present invention is applied have been described, the present invention is not limited to the above-described embodiments, and various changes can be made. For example, in the above example, a metal magnetic film is used as the main core, but a magnetic head in which a closed magnetic path is formed only by a ferrite core without forming such a film on the magnetic core substrate may be used. Needless to say, the same operation and effect as those of the above magnetic head can be obtained with this head. Further, a magnetic recording / reproducing apparatus using such a magnetic head can be applied to a digital signal storage device such as a data streamer in addition to a home digital VTR.

[0082]

According to the method of manufacturing a magnetic head of the present invention, track width regulating grooves having substantially the same shape and different groove depths are alternately formed, and the track width regulating grooves having different groove depths are aligned. In this way, by providing a displacement corresponding to the difference in the groove depth of the track width regulating groove to the abutting position of the magnetic gap forming protrusion of each magnetic core half, the displacement amount of the magnetic gap in the track width direction is fixed. High-precision butting adjusted.

The angle formed by the center line between the abutting surface of the magnetic gap forming protrusion and the wall surface of the track width regulating groove facing the magnetic recording medium and the azimuth direction of the adjacent recording track is equal to the angle between the magnetic gap and the adjacent magnetic track. A magnetic head capable of suppressing crosstalk from an adjacent channel at the time of reproduction is manufactured by giving a deviation so as to be larger than an angle formed between the recording track and the azimuth direction.

In the magnetic head manufactured by such a manufacturing method, the track width regulating grooves have substantially the same shape, and the track width regulating grooves facing each other and the track width regulating grooves adjacent to each other have the same groove shape. The position of the inflection point is different in the groove depth direction, and a deviation in the track width direction is given to the abutting position of the magnetic gap forming protrusion of each magnetic core half. When reproducing, crosstalk from an adjacent channel can be suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a state in which a magnetic head reproduces a recording pattern on a magnetic tape.

FIG. 2 is a schematic diagram showing a state in which a magnetic head reproduces a recording pattern of a magnetic tape when a deviation of a magnetic gap in a + direction occurs.

FIG. 3 is a schematic diagram illustrating a state in which a magnetic head reproduces a recording pattern of a magnetic tape when a magnetic gap in a negative direction is displaced;

FIG. 4 is a characteristic diagram showing a relationship between an error rate and C / N in the case of a deviation of a magnetic gap in a + direction.

FIG. 5 is a characteristic diagram showing a relationship between an error rate and C / N when a magnetic gap is shifted in a negative direction.

FIG. 6 is a perspective view showing an example of a magnetic head to which the present invention is applied.

FIG. 7 is a perspective view showing a manufacturing process of the magnetic head, and showing a process of making a substrate flat.

FIG. 8 is a perspective view illustrating a step of forming a winding groove and a glass groove in a substrate, illustrating a manufacturing process of the magnetic head.

FIG. 9 is a perspective view showing a process of manufacturing the magnetic head, showing a process of forming a track width regulating groove and a projection on a substrate.

FIG. 10 is an enlarged perspective view of a part a in FIG. 9, showing a track width regulating groove.

FIG. 11 is a perspective view illustrating a step of cutting the substrate, showing a step of manufacturing the magnetic head.

FIG. 12 is a perspective view showing a process of manufacturing the magnetic head, showing a process of forming a metal magnetic film.

13 is an enlarged perspective view of a portion d in FIG. 12, showing a state where a metal magnetic film is formed in a track width regulating groove and a gap portion.

FIG. 14 is a perspective view showing a step of manufacturing the magnetic head, showing a state in which cut substrates are joined together by butting.

FIG. 15 is a schematic diagram illustrating a manufacturing process of the magnetic head, and illustrating a process of adjusting a direction in which a magnetic gap is caused to shift and abutting the gap.

FIG. 16 is a perspective view showing a step of manufacturing the magnetic head, showing a step of cylindrically polishing the sliding surface of the magnetic recording medium.

FIG. 17 is a perspective view showing a step of manufacturing the magnetic head, and showing a step of cutting into head chips of a predetermined size.

FIG. 18 is a plan view schematically showing an example of a magnetic head to which the present invention is applied.

FIG. 19 is a plan view schematically showing another example of the magnetic head to which the invention is applied.

FIG. 20 is a plan view schematically showing another example of the magnetic head to which the invention is applied.

[Explanation of symbols]

1, 2, magnetic core substrate, 3, 4, 27 metal magnetic film,
5,6 magnetic core half, 7,8 gap forming surface, 9,
10, 11, 12, 24, 24a, 24b Track width regulating groove, 21 substrate, 21a, 21b magnetic core block (substrate), 24A magnetic gap forming protrusion, O1,
O2 Inflection point of track width regulating groove, Tw track width, F
The center line between the butting surface of the magnetic gap forming protrusion and the wall surface of the track width regulating groove facing the same, the angle formed by the θ magnetic gap and the azimuth direction of the adjacent recording track, the butting of the θ1 magnetic gap forming protrusion Angle between the center line between the surface and the wall surface of the track width regulating groove opposed thereto and the azimuth direction of the adjacent recording track, δ the amount of deviation of the magnetic gap in the track width direction, θ2 the first inclined surface and the gap forming surface Angle with the perpendicular to the angle, θ3
The angle formed between the inclined surface of and the perpendicular of the gap forming surface, H1
Projection for forming magnetic gap

Claims (4)

[Claims] A pair of magnetic core halves each having a track width regulating groove formed thereon and a magnetic gap forming projection formed thereon are joined and integrated so that the track width regulating groove forming surfaces face each other. In a magnetic head in which a magnetic gap having a predetermined azimuth angle is formed between abutting surfaces of gap forming projections, each track width regulating groove has substantially the same shape, and the track width regulating grooves facing each other are formed. In the track width regulating grooves adjacent to each other, the position of the inflection point in the groove shape is set to a position different in the groove depth direction, and a deviation in the track width direction is abutted by the magnetic gap forming protrusion of each magnetic core half. A magnetic head, which is provided. 2. An angle between a center line between an abutting surface of a protrusion for forming a magnetic gap and a wall surface of a track width regulating groove opposed to the magnetic recording medium and an azimuth direction of an adjacent recording track. 2. The magnetic head according to claim 1, wherein the deviation is larger than an angle between the azimuth direction of the adjacent recording track and the azimuth direction. 3. A pair of magnetic core halves, each having a track width regulating groove formed thereon and a magnetic gap forming projection formed thereon, are joined and integrated so that the track width regulating groove forming surfaces face each other. In a method of manufacturing a magnetic head for forming a magnetic gap having a predetermined azimuth angle between butting surfaces of gap forming projections, track width regulating grooves having substantially the same shape and different groove depths are alternately formed, and these groove depths are formed. By aligning the track width regulating grooves having different lengths, a deviation corresponding to the difference in the groove depth of the track width regulating groove is provided at the abutting position of the magnetic gap forming protrusion of each magnetic core half. A method of manufacturing a magnetic head. 4. An angle formed by a center line between an abutting surface of a protrusion for forming a magnetic gap and a wall surface of a track width regulating groove opposed thereto and an azimuth direction of an adjacent recording track is equal to the magnetic gap and the adjacent magnetic track. 4. The method of manufacturing a magnetic head according to claim 3, wherein the misalignment is provided so as to be larger than the angle formed between the recording track and the azimuth direction.