JPH05151523A - Magnetic head and production thereof - Google Patents

Abstract

PURPOSE:To provide the magnetic head which is improved in head efficiency while the advantages of the magnetic head consisting of alloy thin films are effectively utilized and which is hardly satd. in a gap part and the process for production thereof. CONSTITUTION:This magnetic head has a rear core part 11 consisting of a laminate of magnetic alloy thin films 12 and nonmagnetic insulating films 13 laminated in a track width direction, a winding 23 wound in this rear core part 11 and a front core part 18 consisting of the magnetic alloy films 23 deposited on the end face of the rear core part 11 facing a magnetic recording medium. A front gap part 21 which is formed along the lamination direction of the laminate and is formed down to a prescribed depth from the front core 18 part is provided on the magnetic core constituted of the rear core part 11 and the front core part 18 and is formed to the length in the track width direction smaller than the thickness of the magnetic core.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head, and more particularly to an alloy thin film magnetic head suitable for high density and wide band recording / reproduction of HDTV VTRs and digital VTRs.

[0002]

2. Description of the Related Art In recent years, HDTV (High Definition Television)
2. Description of the Related Art A magnetic recording / reproducing apparatus for recording wideband signals at high density, such as a commercial VTR and a digital VTR, has been actively developed. Along with this, recording media such as metal vapor deposition media and alloy powder media suitable for high density recording have come to be used. These media have a coercive force of 1000 to 1500.
Oersted and very large, 2 of that of iron oxide media
~ 3 times more.

High density recording on such a high coercive force medium with a magnetic head having a narrow gap is almost impossible with a ferrite head having a maximum magnetic flux density of about 5000 gauss, which has been generally used conventionally. Therefore, a so-called alloy thin film magnetic head utilizing a high saturation magnetic flux density of a magnetic alloy material has been proposed as a high-density / broadband magnetic head (for example, Japanese Patent Laid-Open No. 1-258206).

FIG. 23 shows an example of such an alloy thin film magnetic head. A pair of magnetic cores 1 is composed of a magnetic alloy thin film 2 and Si.
And a non-magnetic insulating film 3 such as O ₂ is alternately laminated.
This laminated body is held between a pair of non-magnetic substrates 4 and 5. Laminating the magnetic alloy thin film 2 and the non-magnetic insulating film 3 is
This is to prevent eddy current loss. A magnetic gap 6 is formed between the pair of cores 1. A winding hole 7 for winding a winding (not shown) around the core 1 is formed in one of the cores 1, and a pair of cores 1 are integrated by a bonding glass 8.

In such an alloy thin film magnetic head, the track width is easy to control because the thickness of the laminated body of the magnetic alloy film 2 and the nonmagnetic insulating film 3 corresponds to the track width. In addition, since a head can be created by thin film technology, a track that is narrower than a bulk type head such as a ferrite head or a MIG (metal in gap) head whose track width is regulated by machining is used. Can be easily realized. Furthermore, since the magnetic core 1 forming the magnetic circuit has only the track width throughout, the inductance per number of turns of the winding is smaller than that of other bulk type heads.

However, such an alloy thin film head has the following problems. Generally, in order to increase the recording density, it is necessary to narrow the track of the magnetic recording medium and the gap of the magnetic head. When the magnetic head has a narrow gap, the magnetic resistance of the magnetic gap decreases, and the head efficiency decreases. As a method of obtaining high head efficiency even in a narrow gap, there are methods of reducing the gap depth and shortening the magnetic path length of the core. Reducing the gap depth is not preferable because it shortens the life of the head, and unless the magnetic path length is too short, the effect is not improved and it is not practical. Therefore, in order to increase the head efficiency, it is necessary to increase the thickness of the core to reduce the magnetic resistance of the core and reduce the leakage flux.

However, in the above-mentioned alloy thin film magnetic head, the thickness of the laminated body becomes the track width, which facilitates the control of the track width, while the core thickness is made thin to cope with the narrowing of the track. Therefore, the magnetic resistance of the core cannot be lowered, and the saturation of the core becomes a problem.

In order to solve these problems, as shown in FIG. 24, the thickness of the laminated body of the magnetic alloy film 2 and the non-magnetic insulating film 3 in the portion excluding a part of the core 1 on the medium facing surface side is changed. There is also proposed an alloy thin film head in which the width (size in the track width direction) of the rear gap portion of the magnetic gap 6 is increased by increasing the size.

The head having this structure has an advantage that the magnetic resistance of the core 1 is lowered, but a part of the magnetic flux entering the front gap portion of the magnetic gap 6 is a portion where the laminated body constituting the core 1 is thin. Is blocked by the non-magnetic insulating film 3 of the outer layer at the boundary between the thick portion and the thick portion, and it is difficult for the non-magnetic insulating film 3 to enter the inner layer of the laminated body, and the magnetic resistance is not reduced as expected. Further, since the thickness of the core 1 on the medium facing surface side is uniformly the same as the track width, the effect of narrowing down the magnetic flux due to the difference between the track width and the core thickness cannot be obtained. For these reasons, improvement in head efficiency cannot be expected so much, and measures to saturate the gap are not so effective.

Further, there has been proposed a method of increasing the core thickness other than near the gap of the laminating head. Figure 25
Is an example thereof (Japanese Patent Laid-Open No. 62-139109). After forming a laminated body 1 composed of a magnetic alloy film 2 and a non-magnetic insulating film 3 on non-magnetic substrates 4 and 5, a part of the laminated body 1 is designated by the reference numeral. By digging as shown by 9, the thickness of the laminated body 1 is increased with respect to the track width. In this head, the thickness of the laminated body 1 is certainly thicker than the track width, and although the efficiency is improved to some extent as compared with the conventional laminating head, the magnetic path is divided by the insulating nonmagnetic film. However, there is a drawback that the ferrite head is used for efficiency and the TSS (Tilted S) is used for saturation characteristics when used as a recording head.
endust Sputterd) Each head is inferior.

[0011]

As described above, in the conventional alloy thin film magnetic head, when the thickness of the core composed of the laminated body of the magnetic alloy film and the nonmagnetic insulating film is made equal to the track width, Since it is necessary to reduce the thickness of the core in order to deal with the narrow track, there is a problem that the magnetic resistance of the core becomes high.

Also, in the case where the magnetic resistance of the core is lowered by increasing the width of the rear gap portion by increasing the thickness of the laminated body except a part of the core on the medium facing surface side, Not only can the magnetic flux flow be easily blocked by the non-magnetic insulating film of the laminated body, but the effect of narrowing the magnetic flux due to the difference between the track width and the total core thickness cannot be expected, resulting in poor head efficiency and measures against saturation of the gap. There was a problem that it was not enough.

The present invention has been made in view of the above problems, and improves head efficiency while taking advantage of an alloy thin film magnetic head having a high saturation magnetic flux density and capable of high density recording on a high coercive force medium. Another object of the present invention is to provide a magnetic head in which the gap portion is less likely to be saturated and a method for manufacturing the magnetic head.

[0014]

In order to solve the above-mentioned problems, a magnetic head according to the present invention comprises a rear core portion composed of a laminated body of a magnetic alloy film and a non-magnetic insulating film laminated in the track width direction. A winding wound around the rear core portion, a front core portion formed of a magnetic alloy film adhered to an end surface of the rear core portion facing the magnetic recording medium, and a magnetic core including the front core portion and the rear core portion. The front gap portion from the front core portion to a predetermined depth is formed in the core along the laminating direction of the laminated body, and the length in the track width direction is smaller than the thickness of the magnetic core. And a magnetic gap having a widthwise length equal to the thickness of the magnetic core.

Further, according to the present invention, when manufacturing the magnetic head having such a structure, a step of alternately laminating the first magnetic alloy film and the nonmagnetic insulating film to a predetermined thickness on the nonmagnetic substrate to obtain a laminated body, A step of forming a first block by stacking and adhering a plurality of the laminated bodies together, a step of cutting the first block in a direction parallel to the laminating direction to form a second block, A step of depositing a second magnetic alloy film on one end surface of the second block, and a step of forming a plurality of predetermined shapes from the second magnetic alloy film side to a predetermined depth on the second magnetic alloy film and the second block. A step of forming grooves at predetermined intervals, and a direction in which the second block and the second magnetic alloy film that have undergone this step are perpendicular to the thickness direction of the second magnetic alloy film and parallel to the stacking direction of the stacked body. At a position that divides the groove into two and an intermediate position of the groove. Cutting to form the third and fourth blocks, and the cutting surfaces of the third and fourth blocks are opposed to each other so that the bonding material enters the groove portion by a predetermined bonding material. A step of adhering to form a fifth block, and a position at which the groove is divided into two in a direction perpendicular to the thickness direction of the second magnetic alloy film and perpendicular to the laminating direction of the laminated body. And a step of forming a rear core portion made of the laminated body and a front core portion made of the second magnetic alloy film, and winding the rear core portion. ..

Further, according to the present invention, at least the thickness of the magnetic alloy film and the thickness of the laminated body of the magnetic alloy film and the non-magnetic insulating film in the vicinity of the end face facing the magnetic recording medium are made thinner as they approach the front gap. Is characterized by.

Further, according to the present invention, at least the thickness of the magnetic alloy film and the thickness of the laminated body of the magnetic alloy film and the non-magnetic insulating film in the vicinity of the end face facing the magnetic recording medium are reduced as the thickness approaches the front gap. In addition, the number of layers of the non-magnetic insulating film in the laminated body is reduced in the front gap portion and its vicinity.

[0018]

According to the present invention, since the entire magnetic core including the rear core portion and the front core portion is made of the magnetic alloy film as the magnetic material, it is possible to sufficiently record on the magnetic recording medium having a high coercive force. The basic features of the magnetic head can be obtained.

Further, the width of the front gap portion is narrower than the width of the rear gap portion, in other words, the thickness of the laminated body of the magnetic alloy film and the non-magnetic insulating film forming the rear core portion is thicker than the track width, so that the width is narrow. Even when made into a track, the magnetic resistance of the rear core part is kept low, and saturation of the magnetic core is also avoided.

Since the front core portion is composed of a magnetic alloy film alone, if the thickness of this magnetic alloy film is set to be equal to or larger than the gap depth of the front gap portion, the magnetic flux entering the front gap portion will be the same as the conventional one. And flows into the rear core without being blocked by the non-magnetic insulating film. Further, since the width of the front gap portion is smaller than the thickness of the magnetic core, the effect of narrowing down the magnetic flux due to the difference between the track width and the thickness of the magnetic core can be obtained.

Further, according to the present invention, the magnetic core is constituted by the laminated body of the magnetic alloy film having the high saturation magnetic flux density and the non-magnetic insulating film, and the thickness and laminated layer of the magnetic alloy film near the end face facing the magnetic recording medium. By reducing the thickness of the body as it gets closer to the front gap part, not only the characteristics suitable for the magnetic recording medium with high coercive force as described above can be obtained, but also most of the thickness of the laminated body is equal to the front gap part. Since it is thicker than the width (corresponding to the track width), the magnetic resistance of the core is suppressed to be low even when the track is narrowed, and the reproduction efficiency is improved. Also, saturation of the magnetic core is less likely to occur,
Good reproduction becomes possible. Moreover, since the thickness of the laminated body is thin in the front gap portion, the effect of narrowing down the magnetic flux can be obtained, so that the saturation characteristics of the front gap portion with respect to the narrow track and the narrow gap are significantly improved, and the high density recording The characteristics are improved.

[0022]

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

FIG. 1 is a perspective view of a magnetic head according to an embodiment of the present invention. In FIG. 1, a pair of rear core parts 1
1 is a magnetic alloy thin film 12 and a non-magnetic insulating film 13 such as SiO _2.
And are alternately laminated by sputtering or the like,
This laminated body is held between a pair of non-magnetic substrates 14 and 15,
One of the substrates 14 and 15 is adhered to the laminate with an adhesive 16. The pair of rear core portions 11 are integrated by bonding glass, and a rear gap 17 is formed between them.

The soft magnetic material used for the magnetic alloy thin film 12 is preferably a material having a high saturation magnetic flux density and a high magnetic permeability, such as sendust, an iron-based amorphous material, and a cobalt-based amorphous material. The non-magnetic substrates 14 and 15 are made of a ceramic material which is excellent in workability and wear resistance and has a small expansion coefficient difference from the magnetic alloy thin film 12.

On the other hand, on the end surface (medium facing surface) of the rear core portion 11 facing the magnetic recording medium, a front core portion 18 made of a magnetic alloy thin film made of the same material as the magnetic alloy thin film 12 used for the rear core portion 11 is sputtered. And the like. The rear core portion 11 and the front core portion 18 form a magnetic core. The front core portion 18 is provided with notched grooves 19 at both ends in the track width direction (thickness direction of the magnetic core), and the front gap portion 21 is provided between these notched grooves 19 along the track width direction.
Are formed. That is, the front gap portion 21
Is regulated by the notch groove 19 to be equal to the desired track width, and is narrower than the rear gap portion 17. The notch groove 19 is filled with a bonding glass 20.

The winding hole 2 is formed in one of the pair of rear core portions 11.
2 is formed, and the winding wire 23 is wound through the winding hole 22. A recording current is supplied and a reproduction signal is taken out through the winding 22. With the magnetic head having such a structure, the following excellent effects can be expected.

(1) This magnetic head has a rear core portion 11
Since the entire magnetic core including the front core portion 18 and the front core portion 18 is configured by using a magnetic alloy thin film having a high saturation magnetic flux density as a magnetic material, the conventional alloy thin film magnetic head shown in FIGS. 23, 24 and 25 is used. Similarly, characteristics suitable for a magnetic recording medium having a high coercive force can be obtained.

(2) The thickness of the laminated body of the magnetic alloy thin film 12 and the nonmagnetic insulating film 13 forming the rear core portion 11 is thicker than the width of the front gap portion 21, that is, the track width on the magnetic recording medium, and Since the magnetic path is not blocked by the magnetic insulating film, the magnetic resistance of the rear core portion 11 can be suppressed to a low value even when the track is narrowed. Therefore, the head efficiency is improved and the reduction of the reproduction output is suppressed. Further, saturation of the magnetic core is less likely to occur, so that better recording can be performed on a magnetic recording medium having a high coercive force.

(3) Since the front core portion 18 is composed of only the magnetic alloy film, the magnetic recording is performed in the front gap portion 21 by making the thickness of this magnetic alloy film equal to or larger than the gap depth of the front gap portion 21. The magnetic flux entering from the medium can almost entirely flow into the rear core portion 11 without being blocked by the nonmagnetic insulating film. This enables good reproduction.

(4) In general, when the track of the magnetic recording medium is narrowed or the gap of the magnetic head is narrowed, saturation of the front gap portion easily occurs. In the magnetic head of this embodiment, since the width of the front gap portion 21 is smaller than the thickness of the magnetic core, the effect of narrowing down the magnetic flux due to the difference between the track width and the thickness of the magnetic core can be obtained, thus narrowing the track and narrowing the gap. The saturation characteristic of the front gap portion 21 with respect to is significantly improved, and the high density recording characteristic is improved.

Next, an example of the manufacturing process of the magnetic head of this embodiment will be described with reference to FIGS. First, FIG.
A non-magnetic substrate 31 whose surface is polished as shown in (a) is prepared, and as shown in FIG. 2 (b), a first magnetic alloy made of a soft magnetic material to form the rear core portion 11 in FIG. 1 is prepared. Membrane 3
2 and a non-magnetic insulating film 33 such as SiO ₂ are alternately formed by a thin film forming technique such as sputtering, and are laminated until the thickness becomes a predetermined amount thicker than a desired track width.

Next, the laminated body of the non-magnetic substrate 31, the magnetic alloy film 32 and the non-magnetic substrate 33 of FIG. 2B is shown in FIG.
As shown in FIG. 3, a plurality of sheets are further stacked and they are bonded with an adhesive (corresponding to 16 in FIG. 1) to form the first block 34. Next, the first block 34 is shown in FIG.
By cutting along the line A, that is, in the direction parallel to the stacking direction, the second block 35 shown in FIG. 2D is formed.

Next, one end surface of the second block 35, which is the medium facing surface, is polished, and the surface is further etched to remove processing strain. Then, as shown in FIG. 3A, as shown in FIG. The second magnetic alloy film 36 that will become the front core portion 18 is deposited by sputtering or the like. The thickness of the magnetic alloy film 36 is made slightly thicker than the desired gap depth of the front gap portion 21 of FIG.

Next, as shown in FIG. 3B, the second magnetic alloy film 36 and the second block 35 have a predetermined shape, for example, a predetermined shape from the magnetic alloy film 36 side to a depth equal to or larger than a desired gap depth. Hexagonal (or elliptical) grooves 37 as shown in the drawing are formed vertically and horizontally at predetermined intervals. This groove 3
7 is the cutout groove 19 in FIG. 1. When the shape of the groove 37 is hexagonal, the cutout groove 19 has a V-shape as shown in FIG. If the shape is elliptical, the notch groove 19 has a U-shape. The groove 37 may be formed by etching using the photoresist pattern formed on the magnetic alloy film 36, or by laser beam processing.

Next, the member shown in FIG. 3B is cut along the lines B and C. That is, the groove 37 is cut at a position perpendicular to the thickness direction of the magnetic alloy film 36 and parallel to the stacking direction of the laminated body of the blocks 35 (on the line B) and at an intermediate position of the groove 37 (on the line C). As a result, FIG. 3 (c) (d)
The third and fourth blocks 38 and 39 as shown in FIG. Next, the winding groove 22 is formed in the fourth block 39.

Next, the blocks 38 and 3 thus obtained
9, the magnetic gap facing surface (the surface facing the rear gap 17 and the front gap 21)
And the surface is etched to remove processing strain, and then a gap material (non-magnetic film) is formed on the gap facing surface of the block 38 by sputtering.

Next, the blocks 38 and 39 are made to face each other with their cut surfaces (gap facing surfaces) facing each other and bonded with a bonding glass 40 as shown in FIG. 3 (e) to form a fifth block 41. .. At this time, the bonding glass 40 is made to enter the groove 37.

Then, after polishing the surface of the magnetic alloy film 36 which is the medium facing surface of the fifth block 41 so that the cross section has an arc shape, along the line D in FIG. 3E, that is, the magnetic alloy. The groove 37 is cut at a position that divides the groove 37 in a direction parallel to the thickness direction of the film 36 and parallel to the stacking direction of the stacked body of the blocks 35. As a result, the magnetic core in which the rear core portion 11 and the front core portion 18 shown in FIG. 1 are integrated is obtained. In this magnetic core, of course, each gap part 1 in FIG.
7, 21, a groove 19, a bonding glass 20, a winding hole 22 and the like are also formed. Therefore, the magnetic head of FIG. 1 is completed by mounting the winding in the winding hole of the magnetic core.

In the magnetic head of FIG. 1, the thickness of the magnetic core is uniform, that is, [thickness of the rear core portion 11 + thickness of the non-magnetic substrates 14 and 15] throughout.
For example, depending on the difference in tape tension and tape thickness given to the recording medium (magnetic tape), the medium facing surface (tape sliding surface) side is cut to an appropriate width to maintain a good interface between the tape and head. It is possible to appropriately implement the device of (1) as in the conventional case.

Next, another embodiment of the present invention will be described. 4A and 4B are a perspective view of a magnetic head according to another embodiment and a front view seen from the magnetic recording medium facing surface side.
The parts corresponding to those in FIG. 1 are designated by the same reference numerals. The magnetic head of this embodiment is characterized in that in the laminated body 10 of the magnetic alloy thin film 12 and the non-magnetic insulating film 13 forming the magnetic core,
The point is that the film thickness of the magnetic alloy thin film 12 is reduced as it approaches the front gap portion 21 of the magnetic gap. Also,
Along with this, the overall thickness of the laminated body 10 also becomes smaller as it gets closer to the front gap portion 21 with respect to the thickness D at a position away from the front gap portion 21,
The front gap portion 21 has a thickness d corresponding to the track width on the magnetic recording medium.

Also in this embodiment, the same effect as that of the previous embodiment can be obtained. That is, since the magnetic core is formed by using the magnetic alloy film having the high saturation magnetic flux density as the magnetic material, the characteristics suitable for the magnetic recording medium having the high coercive force can be obtained.
Further, since most of the thickness of the laminated body 10 is thicker than the width of the front gap portion 21, that is, the track width on the magnetic recording medium, the magnetic resistance of the core is kept low even when the track is narrowed, and the non-magnetic property is maintained. Since the magnetic path is not cut off by the body, head efficiency is improved and reproduction output is not reduced.

Further, since the thickness of the laminated body 10 which is the magnetic core is thin in the front gap portion 21, the effect of narrowing down the magnetic flux is obtained, and the saturation of the magnetic core hardly occurs. Good recording can be performed on the recording medium, the saturation characteristics of the front gap portion 21 with respect to a narrow track and a narrow gap are significantly improved, and high density recording / reproducing characteristics are improved.

Here, in the conventional magnetic head shown in FIG. 24, a part of the magnetic flux entering the front gap part from the magnetic recording medium is at the boundary between the thin part and the thick part of the laminated body. Since the non-magnetic insulating film 3 of the outer layer blocks it and it is difficult for the non-magnetic insulating film 3 to enter the laminated body of the outer layer, the magnetic resistance is not reduced and the efficiency is not improved so much. On the other hand, in this embodiment, the thickness t of the magnetic alloy thin film 12 is reduced to s as it approaches the front gap portion 21, so that the magnetic flux entering the front gap portion 21 from the magnetic recording medium is a non-magnetic insulating film. There is no interruption at 13.
Therefore, the decrease in efficiency can be further reduced, and good reproduction can be performed over a wide band.

When the degree of narrowing down is increased, that is, when the difference in thickness between D and d in the laminated body 10 is increased, the thickness s of the magnetic alloy thin film 12 in the front gap portion 21 becomes too thin. The magnetic properties may deteriorate. As a countermeasure against this, the thickness s of the magnetic alloy film in the front gap portion 21 of the laminated body 10 is
When is larger, the thickness t of the magnetic alloy thin film in the thickest portion of the laminated body 10 becomes too large, so that the eddy current increases and the efficiency decreases.

FIG. 5 shows an embodiment in which this point is improved,
The position where the thickness of the laminated body 10 starts to decrease (edge 10
In the portion from a) to the front gap portion 21, the nonmagnetic insulating film 13 is removed to form a dividing portion 13a. Specifically, in the example of FIG. 5A, the dividing portion 13a is provided substantially in the middle of the edge 10a and the front gap portion 21, and in the example of FIG. 5B, two dividing portions 13a are provided. In addition to this, various modifications can be considered in the method of providing the dividing portion 13a depending on the ratio of the thicknesses D and d of the laminated body 10.

Next, an example of a manufacturing process of the magnetic head shown in FIGS. 4 and 5 will be described with reference to FIGS. First, the non-magnetic block 50 having the protrusions 51 as shown in FIG. 7 is manufactured. Next, as shown in FIG. 8, a magnetic alloy film and a non-magnetic insulating film are alternately formed on the non-magnetic block 50 to form a laminated film 52 to be the laminated body 10.
At this time, if the laminated film 52 is formed by a normal method by sputtering or the like, the film thickness cannot be changed in the focusing portion 53 of the laminated film 52. Therefore, as shown in FIG. 9, a shielding plate 54 is installed on the non-magnetic block 50 on the side of the sputter source to shield the metal magnetic particles 55 flying from the sputter source. The shielding plate 54 is constituted by, for example, a filter 56 in which the number of passing magnetic metal particles 55 increases toward the upper side of the drawing as shown in FIG. 10, or a wedge-shaped shielding plate 57 as shown in FIG.

FIG. 12 is a perspective view when the filter 56 of FIG. 10 is used as the shield plate 54. In this case, the upper end 56a of the filter 56 is aligned with the edge 50a of the non-magnetic block 50, and the boundary 56b of the filter 56 is aligned with the top of the protrusion 51 when viewed from the flying direction of the metal magnetic particles 55. The filter 56 has innumerable holes of a size large enough for the metal magnetic particles 55 to pass through. Either the diameter of the holes should be increased toward the top of the drawing of FIG. 10 or the number should be increased. One or both measures are taken.
The diameter of the metal magnetic particles 55 is several angstroms to several 1
Since the thickness is 0 angstrom, it is necessary to prevent the diameter of the hole from becoming too small so that the metal magnetic particles 55 can pass through the hole even in the lower layer. Further, if the distance between the holes is made too large, there will be a portion on the non-magnetic block 50 where the metallic magnetic particles 55 do not reach, or even if it reaches, the number is small compared to the vicinity thereof. The film thickness may be uneven. As a countermeasure against this, for example, a method of swinging the filter 56 in the direction of the double-headed arrow 58 can be considered.

The filter 56 has a structure in which the layer below the boundary 56b cannot completely pass through the metallic magnetic particles 55. When sputtering or the like is performed through such a filter 56, the number of flying magnetic metal particles from the edge 50a to the top of the protrusion 51 is reduced, and the film thickness can be reduced. In this case, when the magnetic head of FIG. 4 is manufactured, the shield plate 54 is completely removed when the non-magnetic insulating film 13 is formed, and when the magnetic head of FIG. When the non-magnetic film is not formed on the gap side of the divided portion 13a of 13, the portion may be entirely covered with a shielding plate that does not allow the metal magnetic particles 55 to pass.

FIG. 13 is a perspective view when the wedge type shield plate 57 of FIG. 11 is used as the shield plate 54. Again,
When viewed from the flying direction of the metal magnetic particles 55, the upper end 57a of the shield plate 57 is aligned with the edge 50a of the non-magnetic block 50, and the boundary 57 between the wedge-shaped portion and the base end portion of the shield plate 57.
b is aligned with the top of the protrusion 51. However, since there is a portion where the magnetic metal particles 55 do not reach, the double-headed arrow 5
When swinging in the direction of 8, the length of the bottom part of the wedge-shaped part is 5
It is necessary to swing it at a distance of 9 or more.

It should be noted that, as the shield plate 54, another structure shown in FIG.
It is also possible to use a disc-shaped product as shown in (a) and (b) and rotate it. As described above,
The laminated film 52 of FIG. 8 is formed.

Next, as shown in FIG. 15, after the excess magnetic alloy film is removed and flattened by polishing or etching so that the height of the protrusion 51 and the height of the magnetic alloy film match,
On the non-magnetic block 50, a block bonding glass layer 61 made of high melting point glass or crystallized glass is formed.

Next, two non-magnetic blocks 50 which have undergone the steps up to FIG. 15 are prepared, and as shown in FIG. 16, both blocks are abutted so that the block bonding glass layer 61 sides face each other, and high temperature fusion is performed. Are integrated with each other to form an integrated block 62.

Next, a plurality of blocks shown in FIG. 16 are stacked, and a stacked block 63 as shown in FIG. 17 is formed in the same manner by using glass having a melting point slightly lower than that of the block bonding glass layer 61. In addition, without going through the process of FIG.
It is also possible to directly manufacture the stacking block 63 of FIGS. 14 to 17. In this case, the block bonding glass may have the same melting point. Next, FIG.
By cutting the stacked block 63 of No. 7 along the alternate long and short dash line, a cutting block 64 shown in FIG. 18 is manufactured.

Next, as shown in FIG. 19, a winding window groove 66 and a glass-fusing groove 67 for fusing are processed in the cutting block 64 of FIG. At this time, the winding window groove 65 is formed so as to include the boundary 65 between the portion with and without the protrusion 51 shown in FIG. This prevents the cross-sectional area of the rear core from becoming smaller.

Next, the cut surface 68 shown in FIG.
As shown in 0, when the thickness of the front gap portion 21 of the laminated body 10 becomes the thickness d corresponding to the track width on the magnetic recording medium, the cut surface 68 is finished by a method such as etching. After that, a gap material 69 such as SiO ₂ having a predetermined film thickness is formed on the cut surface 68 as shown in FIG.

Next, two blocks 64 shown in FIG. 21 are prepared, and both blocks are provided with a gap material 69 as shown in FIG.
Butt so that they face each other, low melting point glass 70
Gap fusion using. Normally, the gap material 69 is not formed on one of the two blocks.
At this time, one half body 71 may be the one shown in FIG. 21, and the other half body 72 may be one without winding groove processing as shown in FIG. A grooved product may be used. Finally, after the side facing the magnetic recording medium (sliding surface) is cylindrically polished, the adhesive surface 7
By slicing along 3, the magnetic head chip shown in FIG. 4 or 5 is completed. The technique using the shield plate 54 can be generally used for sputtering and vapor deposition.

In the embodiment of FIG. 4, the thickness of the laminated body 10 is increased on the back side of the magnetic head (the side opposite to the surface facing the magnetic head), but as shown in FIG. The thickness is made uniform in the vertical direction (the depth direction of the magnetic gap), that is, the stacked body 10 near the magnetic gap.
May be thinned in the entire depth direction of the magnetic gap.

[0058]

As described above, according to the present invention, since the entire magnetic core uses the magnetic alloy film as the magnetic material, not only the characteristics suitable for the magnetic recording medium having high coercive force but also the rear core portion can be obtained. Is a laminated body of a magnetic alloy film and a non-magnetic insulating film, the front core portion is composed of only the magnetic alloy film, and the medium facing surface has a structure in which the laminated body is not exposed. Is made thicker than the track width to reduce the magnetic resistance, and at the same time, the magnetic flux entering the front gap is not blocked by the non-magnetic insulating film.
Even in a high frequency band such as a recording signal of an HDTV VTR, excellent performance can be obtained in terms of head efficiency.

Further, since the width of the front gap portion is regulated to be smaller than the thickness of the magnetic core, the effect of narrowing down the magnetic flux due to the difference between the track width and the core thickness causes the front even with a narrower track or narrower gap. There is an advantage that the saturation characteristic of the gap portion is also significantly improved.

Further, the magnetic core is constituted by the laminated body of the magnetic alloy film and the non-magnetic insulating film, and the thickness of the magnetic alloy film and the laminated body in the vicinity of the end face facing the magnetic recording medium are set to the front gap portion. When the track is narrowed, the magnetic resistance of the core is suppressed to be low by thinning the film as it gets closer to, and good reproduction becomes possible. Moreover, since the thickness of the laminated body is thin in the front gap portion, the effect of narrowing down the magnetic flux can be obtained, so that the saturation characteristics of the front gap portion with respect to the narrow track and the narrow gap are significantly improved, and the high density recording The characteristics are improved.

As described above, according to the present invention, for high density / high frequency recording on a high coercive force medium such as a metal coating medium or a metal vapor deposition medium with a narrow track of about several μm and a short wavelength of about 0.4 μm or less. Even when the gap length is set to 0.2 μm or less and the track width is set to about 10 μm or less, the efficiency decrease due to the increase in the magnetic resistance of the core is small, and at the same time, the magnetic path is not divided by the non-magnetic insulating film, and it is difficult to saturate during recording. Since a sufficient recording magnetic field can be generated, there is little sliding noise at the time of reproduction, and the cross-sectional area of the rear core part can be made sufficiently wide, the magnetic resistance of the core becomes small, and an efficient magnetic head can be provided. it can.

[Brief description of drawings]

FIG. 1 is a perspective view of a magnetic head according to an embodiment of the present invention.

FIG. 2 is a diagram showing a part of a manufacturing process of the magnetic head of the embodiment.

FIG. 3 is a diagram showing another part of the manufacturing process of the magnetic head of the embodiment.

FIG. 4 is a perspective view and a front view of a magnetic head according to another embodiment of the invention.

5 is a front view showing an embodiment obtained by partially modifying the embodiment of FIG.

6 is a perspective view showing another embodiment obtained by partially modifying the embodiment of FIG.

FIG. 7 is a perspective view showing a non-magnetic block for explaining a manufacturing process of the magnetic head of FIG.

FIG. 8 is a perspective view showing a state in which a laminated film is similarly formed on the non-magnetic block.

9 is a diagram for explaining a method of controlling the film thickness of the laminated film of FIG.

FIG. 10 is a cross-sectional view showing a filter which is an example of a shielding plate used in FIG.

FIG. 11 is a cross-sectional view showing another example of the shielding plate used in FIG.

FIG. 12 is a diagram showing an example of using the filter of FIG.

FIG. 13 is a diagram showing an example of use of the shielding plate of FIG.

FIG. 14 is a view showing still another example of the shielding plate used in FIG.

15 is a perspective view showing a state in which an adhesive glass is formed on the non-magnetic block of FIG.

16 is a perspective view showing an integrated block in which two blocks of FIG. 15 are bonded together.

FIG. 17 is a perspective view showing a stacking block using the block of FIG.

FIG. 18 is a perspective view showing a state in which the block of FIG. 17 is cut.

FIG. 19 is a perspective view showing a state in which a winding groove and an adhesive glass flow groove are formed in the block of FIG.

20 is a perspective view showing a state in which the block of FIG. 19 is polished.

21 is a perspective view showing a state in which a gap material is formed on the block of FIG.

FIG. 22 is a perspective view showing a completed state of the head block.

FIG. 23 is a perspective view showing an example of a conventional alloy thin film magnetic head.

FIG. 24 is a perspective view showing another example of a conventional alloy thin film magnetic head.

FIG. 25 is a perspective view showing still another example of a conventional alloy thin film head.

[Explanation of symbols]

11 ... Front core part 12 ... Magnetic alloy thin film 13 ... Non-magnetic insulating film 14 ... Non-magnetic substrate 15 ... Non-magnetic substrate 16 ... Adhesive agent 17 ... Rear gap part 18 ... Front core part (magnetic alloy film) 19 ... Notch groove 20 ... Bonding glass 21 ... Front gap part 22 ... Winding hole 23 ... Winding 31 ... Nonmagnetic substrate 32 ... First magnetic alloy film 33 ... Nonmagnetic insulating film 34 ... First block 35 ... Second block 36 ... second magnetic alloy film 37 ... groove 38 ... third block 39 ... fourth block 40 ... bonding glass 41 ... fifth block

Claims (4)

[Claims] 1. A rear core portion comprising a laminated body of a magnetic alloy film and a non-magnetic insulating film laminated in the track width direction, a winding wound around the rear core portion, and a magnetic recording medium of the rear core portion. A front core portion made of a magnetic alloy film adhered to the facing end surfaces, and a magnetic core formed of the front core portion and the rear core portion are formed along the stacking direction of the stacked body, and a predetermined distance from the front core portion is formed. A magnetic head, characterized in that the front gap portion to the depth comprises a magnetic gap whose length in the track width direction is smaller than the thickness of the magnetic core. 2. A step of obtaining a laminated body by alternately laminating a first magnetic alloy film and a nonmagnetic insulating film to a predetermined thickness on a nonmagnetic substrate, and laminating a plurality of the laminated bodies and adhering them to each other. Forming a second block by cutting the first block in a direction parallel to the stacking direction, and forming a second magnetic alloy film on one end face of the second block. A step of depositing and forming, a step of forming a plurality of grooves having a predetermined shape at predetermined intervals from the second magnetic alloy film side to a predetermined depth in the second magnetic alloy film and the second block, and this step is performed A position that divides the second block and the second magnetic alloy film into two parts in a direction perpendicular to the thickness direction of the second magnetic alloy film and parallel to the stacking direction of the stacked body, and an intermediate position of the groove. And cutting to form third and fourth blocks, Forming a fifth block by adhering the third and fourth blocks so that their cut surfaces face each other and adhering the bonding material with a predetermined bonding material so that the bonding material enters into the groove portion; and The block is cut at a position that bisects the groove in a direction perpendicular to the thickness direction of the second magnetic alloy film and perpendicular to the stacking direction of the stacked body, and the rear core portion and the second 2. A method of manufacturing a magnetic head, comprising: a step of forming a front core portion made of the magnetic alloy film of 1 .; and a step of winding the rear core portion. 3. A core composed of a laminated body of a magnetic alloy film and a non-magnetic insulating film laminated in the track width direction, a winding wound around the core, and a magnetic recording medium facing the core. A magnetic gap having at least a front gap portion from the end face to a predetermined depth, the thickness of the magnetic alloy film and the thickness of the laminated body at least near the end face facing the magnetic recording medium are set to the front. A magnetic head characterized by being made thinner as it gets closer to the gap. 4. A core composed of a laminated body of a magnetic alloy film and a non-magnetic insulating film laminated in the track width direction, a winding wound around the core, and a magnetic recording medium of the core facing the core. A magnetic gap having at least a front gap portion from the end face to a predetermined depth, the thickness of the magnetic alloy film and the thickness of the laminated body at least near the end face facing the magnetic recording medium are set to the front. A magnetic head, wherein the magnetic head is made thinner as it gets closer to the gap portion, and the number of layers of the non-magnetic insulating film in the laminated body is reduced at and near the front gap portion.