JPH04356701A - Composite type magnetic head - Google Patents

Abstract

PURPOSE:To provide a composite type magnetic head to exhibit an excellent recording and reproducing characteristic even to a high coercive force recording medium. CONSTITUTION:Two pieces of substrate blocks 31, 31', cut grooves formed on the substrate blocks 31, 31' as being extended from the side of the surface opposite to the medium to the opposite side and leaving the blocks narrower in width than the width of a track, magnetic films 30, 30' stuck on the cut grooves, a magnetic gap 32 magnetic bodies stuck on the above-mentioned narrow-width block parts form as standing face to face, and a coil winding window 34 formed by cutting a part of the above-mentioned magnetic films 30, 30' are provided.

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 recording and reproducing high frequency signals in VTRs and the like, and particularly to a composite magnetic head suitable for high coercive force recording media.

0002

[Prior Art] It is well known that it is advantageous to increase the coercive force Hc of a magnetic recording medium in a high-density magnetic recording/reproducing device. requires a strong magnetic field. However, since the ferrite material currently used in magnetic heads has a saturation magnetic flux density Bs of about 4000 to 5000 Gauss, there is a limit to the strength of the recording magnetic field that can be obtained, and the coercive force Hc of the magnetic recording medium is about 1000 Gauss. The disadvantage of crossing Ørsted is that the records will be inadequate.

On the other hand, Fe-A, which is a generic name for metallic magnetic materials,
l-Si alloy (called Sendust), Ni-F
Crystalline magnetic alloys such as e-alloy (permalloy), or
Magnetic heads using amorphous magnetic alloys generally have higher saturation magnetic flux density than ferrite materials, and have excellent characteristics such as low sliding noise. However, when the thickness of the generally used track width (10 μm or more) is used, the effective magnetic permeability in the video frequency domain is lower than that of ferrite due to eddy current loss, resulting in a disadvantage that the reproduction efficiency is lowered. Also, in terms of wear resistance, it is several steps inferior to ferrite.

In order to solve the above-mentioned problems, a composite magnetic head has been proposed that combines ferrite and metal magnetic materials to take advantage of the advantages of both.

For example, as shown in a perspective view of the magnetic head core in FIG. 1, a core portion 10 is made of high magnetic permeability ferrite, and a portion 1 near the working gap, which is the main part of the recording action, is formed.
A composite magnetic head has been proposed in which 1 is made of a metal magnetic material formed by physical vapor deposition. Furthermore, in order to narrow the track of a magnetic head for high-density recording, a cutout groove 12 for narrowing the track width is provided in the vicinity of the working gap, and this groove is filled with a reinforcing nonmagnetic material. 13 is a window for coil winding.

FIG. 2 shows a plan view of the recording medium facing surface of the conventional magnetic head. Here, there is a drawback that the coupling boundary portions 14, 14' between the ferrite core portions 10, 10' and the metal magnetic material portions 11, 11' act as a pseudo operating gap, impairing recording and reproducing characteristics. In particular, if the coupling boundaries 14, 14' and the working gap 15 are parallel, a considerable amount of signal will be picked up at the boundaries, resulting in a severe contour effect.

[0007] Furthermore, in order to eliminate the contour effect, a method is known in which appropriate irregularities are provided at the coupling boundary portions 14, 14' between the ferrite core portions 10, 10' and the metal magnetic material portions 11, 11'. However, it is difficult to completely eliminate the contour effect.

As another conventional example, a head having a structure as shown in FIG. 3 is known. In this head, a metal magnetic material 21 having a high saturation magnetic flux density is formed on a non-magnetic substrate 20 to a thickness equal to the track width by sputtering or physical vapor deposition such as vacuum evaporation. After bonding with a thin film, it is divided into two equal parts, the gap abutting surfaces are wrapped, a coil winding window 22 is formed, and the coil winding window 22 is bonded to the gap abutting surface 23 via a prescribed nonmagnetic film. This structure has problems in the gap formation method, is inefficient, has difficulty in achieving gap length accuracy, and has poor yield and productivity.

[0009] Japanese Patent Application Laid-Open No. 169214/1983 shows FIG.
Heads as shown in (d) and (e) have been disclosed. As shown in FIG. 11(A), this head is prepared by preparing a roof-shaped ferrite block 100 with continuous triangles above the winding window 13 shown in FIG. 11(C), and applying sendust to the roof-shaped portion. A magnetic alloy 11 such as an alloy is deposited by a sputtering method or the like to form a composite magnetic block as shown in FIG. A gap abutting surface is formed, and a silicon oxide film is deposited thereon to produce a composite magnetic block 100a that forms one side of the head chip.

Next, as shown in FIG. 11(c), the winding window 13
Composite magnetic block 10 forming the other side of the chip provided with
0b and the above-mentioned 100a are butted together and bonded. After that, cut the part indicated by the dotted line in Figure 11(c), and
A composite magnetic head as shown in (e) is used.

[0011] In the composite magnetic head manufactured in this manner, since the direction of the joint surfaces between the ferrite core parts 10, 10' and the magnetic alloy 11 and the direction of the working gap 15 are oblique to each other, an undesired equivalent head gap is formed. Deterioration of characteristics caused by this can be reduced.

0012

SUMMARY OF THE INVENTION An object of the present invention is to provide a composite magnetic head that exhibits excellent recording and reproducing characteristics even on high coercive force recording media and is easy to manufacture.

[0013]

[Means for Solving the Problems] In order to achieve the above object, the composite magnetic head of the present invention includes two base blocks and a magnetic head that extends from the medium facing surface to the opposite surface of the base block. Magnetism formed by a kerf formed to leave a block with a width narrower than the track width, a magnetic film deposited on the kerf, and a magnetic material deposited on the narrow block portion facing each other. It is characterized by having a gap and a coil winding window that exists by cutting a part of the magnetic film.

[0014] Preferably, the present invention fills the space formed by the magnetic material on the opposing sides of the projections of the two base blocks with a non-magnetic reinforcing member, so that the medium sliding surface is flat. and will not damage the media. Furthermore, the magnetic material at the tip of the protrusion is reinforced, and the strength of the entire head is guaranteed. Furthermore, uneven wear can be prevented by forming the magnetic body substantially symmetrically. It also has the effect of preventing the magnetic film from peeling off.

[0015] It is preferable that the width of the protrusion increases as the distance from the operating gap increases. By doing so, the magnetic material can be efficiently deposited on the side surfaces of the groove, and the contact area with the base block can be increased. In addition, if the apex angle of the protrusion is too large, errors will easily occur in the track width, and if it is too small, the protrusion will become mechanically weak, so the apex angle of the protrusion (or the angle formed by both side surfaces) is 45 Preferably between 90° and 90°.

[0016] The base block is usually Mn--Zn ferrite or Ni--Zn ferrite. Further, the magnetic material may be any material as long as it has a high permeability material with a saturation magnetic flux density higher than that of the base block and a magnetostriction near 0, but typical examples include the well-known Fe-Si alloy, Fe-Al
-Si alloy (so-called sendust alloy), Ni-Fe
Examples include alloys (so-called permalloy alloys) and various high magnetic permeability amorphous alloys. Also, for example, S
Thickness 10 made of non-magnetic material such as iO2, Al2O3
A magnetic material may be used in which nonmagnetic layers of 0 Å to 1 μm and the high saturation magnetic flux density magnetic layers are alternately laminated. In this way, magnetic properties can be improved by alternately laminating magnetic layers and non-magnetic layers.

In order to increase the saturation magnetic flux density in the vicinity of the gap, the working gap forming surface is preferably formed of only the magnetic material, but even if it is formed of both the magnetic material and the base block, it is still a single member. The effect of the present invention is recognized compared to the conventional one formed of a core.

The magnetic film on both sides of the base block protrusion is preferably filled with a non-magnetic material up to the side surfaces of the core.

When the working gap forming surface is made of only the magnetic material having the high saturation magnetic flux density, the width in the track width direction of the base block at the tip of the protrusion is 1 of the track width.
The width of the base block at the tip may be set to 0, that is, the tip may be square. By doing so, the contour effect is reduced to such an extent that it hardly becomes a problem. Furthermore, if the surface of the base block at the tip is processed so that it is not flat, more favorable results can be obtained in terms of the contour effect.

[0020] When the working gap forming surface is composed of both the magnetic material with the high saturation magnetic flux density and the base block, in order to increase the saturation magnetic flux density near the working gap, the width of the magnetic material in the track width direction on the gap forming surface is It is desirable that the sum of the widths is at least twice the width of the base block.

[0021] The thickness of the magnetic material with high saturation magnetic flux density deposited on both sides of the protrusion of the base block is usually
It should be 1/2 or less of the track width. This means that the width in the track width direction of the magnetic material exposed on the surface facing the recording medium in the working gap is equal to or greater than the sum of the thicknesses of the magnetic material deposited on both sides of the base block protrusion. This is because. When the tip of the protrusion of the base block is square, the width of the working gap is approximately the sum of the thicknesses of the magnetic material, so the thickness of the magnetic material is approximately 1 of the track width.
It is better to set it to /2.

[0022] In the present invention, the magnetic material is applied to both sides of the base block protrusion, and if it is applied only to one side, the bonding area between the magnetic material and the base block is small. The magnetic resistance of the magnetic circuit increases,
Furthermore, the thickness of the magnetic material to be deposited must be increased to about the track width, and furthermore, the process becomes complicated because it is deposited only on one side, which is not preferable.

The magnetic head described above consists of two core halves having substantially the same structure as described above except for the coil winding window. , a different structure may be used except that a second magnetic body having a higher saturation magnetic flux density than that of the base block is present on the working gap forming surface. For example, among the high saturation magnetic flux density magnetic bodies facing each other across the working gap made of non-magnetic material, one is the first high saturation magnetic flux density magnetic body composited with the base block in the composite material having the above structure. in,
The other may be a second high saturation flux density magnetic material deposited on top of the composite. In this case, the winding coil can be provided by thin film fabrication techniques. The materials of both magnetic bodies may be the same or different.

In the structure of the composite magnetic head of the present invention, everything other than what is described in this specification follows the conventional technology.

In the composite magnetic head of the present invention, most of the core is made of Mn-Zn ferrite or Ni with high magnetic permeability.
- Made of bulk material of Zn ferrite, the part constituting the working gap part and most of its vicinity are made of magnetic material with high saturation magnetic flux density, such as Fe-Si system, Fe-A
It is made of a crystalline alloy or an amorphous alloy such as l-Si type or Ni-Fe type, and is obtained by physical vapor deposition such as sputtering or vacuum evaporation. chemical vapor deposition in some cases;
It can also be formed by plating or the like. Further, the magnetic material may be other than metal magnetic material as long as it can be deposited.

[0026]

[Operation] The composite magnetic head according to the present invention has excellent characteristics such as saturation magnetic flux density, effective magnetic permeability, and wear resistance because the head is made of a composite of different materials. Since the bonding boundaries are non-parallel, the negative influence of contour effects can also be reduced.

Furthermore, using two base blocks each having a narrowed portion with a notched groove, a magnetic material is coated on the surface of the groove,
The magnetic bodies of the narrowed portions of the two base blocks face each other across the working gap, and the magnetic films are cut to form a coil winding window. In the present invention, since the notched groove is formed from the medium facing surface to the opposite surface, it is only necessary to form a plurality of grooves in the large block at once and then divide it into small blocks later to form the head. Suitable for mass production. Furthermore, since the coil winding window is formed after the magnetic film is formed on the groove, there is no need to form the magnetic film on the coil window, and it can be formed on the flat groove, resulting in good magnetic properties. Film formation is easy. Furthermore, by forming a magnetic film with good magnetic properties from the medium facing surface to the opposite surface, an excellent magnetic circuit can be constructed.

Furthermore, since the magnetic material is adhered to the surface of the block narrowed by the notched groove, the block portion acts as a core of the magnetic material, and sufficient strength can be obtained. In addition, since the contact area between the block and the magnetic film is large, the magnetic properties are good.

Furthermore, since the space between the magnetic materials on the sides of the projections of the two base blocks is filled with a non-magnetic reinforcing member, the strength of the tips of the projections is guaranteed, and the medium sliding surface is It can be constructed flat, so there is no need to worry about damaging the medium at the edge of the magnetic film. Furthermore, the shape of the magnetic film is symmetrical, so there is no need to worry about uneven wear or step wear.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the magnetic head of the present invention will be explained in detail below using examples.

[Embodiment 1] FIGS. 4(a) and 4(b) are a perspective view and a plan view showing the structure of a composite magnetic head in a first embodiment of the present invention. 30 and 30' form a track part and an operating gap part, and are made of a metal magnetic material with a high saturation magnetic flux density, and are made of Fe-Si, Fe-Al-Si, Ni-F.
It is composed of a crystalline alloy or an amorphous alloy of e.
Each has a composition near zero magnetostriction. On the other hand, 31 and 31' are Mn-Zn ferrite, Ni-Z
It is made of a bulk material with high magnetic permeability such as n-ferrite, and is magnetically connected to the metal magnetic body. Further, a predetermined non-magnetic film is formed at the abutting portion of the pair of metal magnetic materials, thereby forming an operating gap 32.

Note that the track width is narrower than the core width, and a groove is provided to determine the track width. This groove is formed in advance from the front part of the core (medium facing surface side) to the rear part on both sides of the ferrite block, leaving a ferrite part having a width narrower than the track width on the surface of the ferrite block on the gap forming side. The metal magnetic materials 30, 30' are attached to the sides of the remaining ferrite protrusions by a thin film forming technique such as sputtering or vacuum deposition. The grooves are filled with non-magnetic materials 33, 33' such as glass, ceramic, resin, etc. as reinforcing materials. 34 is a window for coil winding.

FIG. 4(b) shows an enlarged view of the magnetic tape sliding surface. In the present invention, the ferrite protrusion 35
, 35' are attached with metal magnetic films 30, 30'. Therefore, the thickness of the metal magnetic material is only about half the track width t, and the film formation time is shortened. On the magnetic tape sliding surface in FIG. 4(b), the ferrite protrusions 35, 35'
If the shape is such that it becomes wider as it moves away from the working gap 32, the film can be efficiently formed by sputtering a metal magnetic film from the working gap surface side when forming the core half. Further, since the metal magnetic film is divided into two, even a single layer film can reduce the influence of eddy current loss. Furthermore, since the shape of the joint between the ferrite part and the metal magnetic film has no parallel part to the working gap 32, there is no concern about deterioration of characteristics due to the contour effect. Furthermore, the ferrite protrusions 35, 35' serve as the core of the metal magnetic film,
Moreover, since it is close to the working gap, wear resistance is guaranteed and mechanical strength is also high. Furthermore, the present invention is suitable for a magnetic head having a track width of ten-odd microns or less because it eliminates the need to cut out grooves for regulating the track width after attaching the metal magnetic film, and it This solves the problem of film peeling that occurs when the membrane peels off.

The composite magnetic head of the present invention described above has i
) At least one set of grooves each consisting of two adjacent grooves are formed on the gap forming side surface of a block made of high magnetic permeability ferrite so as to sandwich a protrusion having a tip having a width narrower than the track width. ii) a step of depositing a magnetic material having a higher saturation magnetic flux density than the ferrite on at least the groove surface of the gap forming side surface of the ferrite block after step i); iii) a step of depositing the magnetic material in parallel; iv) removing unnecessary parts of the non-magnetic material and magnetic material to expose a gap forming surface having a predetermined track width; ) A step of preparing a pair of blocks that have completed step iv) and forming a coil winding window groove on the gap forming side surface of at least one of the blocks so as to be substantially perpendicular to the groove, vi) step v) vii) forming a non-magnetic layer of a required thickness on the gap-forming side surface of at least one of the pair of blocks that has completed step vi); It can be easily manufactured by a manufacturing method comprising a step of facing each other, joining each other to integrate, and viii) cutting the joined blocks at a predetermined position to obtain at least one magnetic core. can.

In step i), the groove may be provided so as to run longitudinally from one edge to the other edge of the face of the block on the gap forming side, or may be provided only on one edge side. Further, in step i), the tips of the projections between the adjacent grooves may be processed so that a flat surface exists or may be processed so that no flat surface exists. Furthermore, in step i), the tips of the protrusions may be at the same level as the flat portions adjacent to the respective sets of grooves, or may be lower than the adjacent flat portions. If the height is lower than the adjacent flat portion, the level difference between the tip of the protrusion and the adjacent flat portion should be equal to or less than the thickness of the magnetic material having the high saturation magnetic flux density, that is, equal to or less than half the track width. If this is not done, the level difference will exist even after the magnetic material is attached to the protrusion, and the step vi
i) becomes difficult.

Hereinafter, in order to understand the structure of the composite magnetic head of the present invention, the manufacturing method thereof will be explained in more detail with reference to the drawings.

Explanatory diagrams of each step of the manufacturing method are shown in FIGS.
Shown in (i).

i) FIG. 8(A) shows two adjacent grooves 42 leaving protrusions narrower than the track width on the surface 41 of the block 40 made of high magnetic permeability ferrite, which becomes the gap abutting surface.
, 42' are provided in parallel. Here, the high magnetic permeability ferrite is composed of a single crystal or polycrystal of Mn--Zn ferrite or Ni--Zn ferrite, and forms the main part of the magnetic core. A metal bond grindstone or a resin bond grindstone having a V-shaped or U-shaped tip is used to form the groove, and the groove is processed with a high-speed dicer or the like. Further, the grooves 42 and 42' can be processed simultaneously by stacking two grindstones. FIG. 8(b) shows an enlarged side view of the grooves 42, 42' machined in the process shown in FIG. 8(a) (hereinafter, the steps corresponding to FIGS. 8(a), 8(b), etc. b), process (b)). Here, the flat part 43 left between each set of grooves is a reinforcement part of the metal magnetic film in the subsequent process, for example, polishing in the process (e) or joining the blocks in the process (h), and becomes.

ii) Step (c) is a step in which a metal magnetic film 44 having a saturation magnetic flux density higher than that of ferrite is deposited by sputtering on the entire gap abutting surface including the groove portion obtained in step (a). Metal magnetic material is Fe
-Si (Si6.5% by weight), Fe-Al-Si alloy (
Sendust), Ni-Fe alloy (permalloy), etc., and amorphous alloys include Co-Fe-S
A well-known metal-metalloid alloy represented by i-B series, a well-known metal-metal alloy such as Co-Ti, Co-Mo-Zr, etc. are used. Other deposition methods such as vacuum evaporation, ion plating, chemical vapor deposition, or plating are also possible, but they have drawbacks such as being able to produce only a limited number of metals and large fluctuations in composition, so sputtering is suitable. Furthermore, the sputtering method has the advantage of high adhesion strength and good penetration into grooves, and is therefore suitable for the method of the present invention. The thickness of the deposited magnetic metal material may be approximately 1/2 of the required track width. Therefore, compared to the conventional method, eddy current loss can be reduced even with a single magnetic film. Furthermore, if necessary, a multilayer film in which nonmagnetic materials are alternately laminated may be used.

iii) Step (d) is a step of filling the metal magnetic film obtained in step (c) with the nonmagnetic material 45 to the extent that at least the remaining grooves are filled. As the non-magnetic material 45, glass, ceramic-based inorganic adhesive, or hard resin is used. Glass is suitable from the standpoint of stability. As long as the metal magnetic film 44 is a crystalline alloy, the glass material can be selected from a wide range of operating temperatures of 800° C. or less. On the other hand, in the case of an amorphous alloy, one must be selected that is at least below the crystallization temperature, and the working temperature must be made into glass at a low melting point of 500° C. or lower.

iv) Step (e) is the unnecessary non-magnetic material 45 and metal magnetic film 44 of the block obtained in step (d).
In this step, the active gap forming surface made of the metal magnetic film with the required track width t is exposed. The removal method is performed by grinding and polishing, and the final finish is a mirror polished surface to obtain a gap abutting surface. Mirror polishing is performed until the track width t is obtained.

v) In step (f), a pair of blocks obtained in step (e) is prepared, and at least one block 40'
This is a step in which a coil winding groove 46 is formed on the gap forming surface, and then a non-magnetic material such as SiO2 or glass is sputtered to a desired thickness on the gap forming surface to form a gap forming film.

vi) Step (g) is the pair of blocks 4
This is a step of abutting the gap abutting surfaces of 0 and 40' so that the track portions match each other and joining and integrating them while applying heat and pressure. In this case, if the non-magnetic material 45 filled in the groove is made of glass, the bonding is done by mutual glass; if resin is used, a cutout groove is formed separately in a part of the coil winding window and in the rear joint part. This is done using resin.

vii) FIG. 8(H) shows the magnetic tape sliding surface of the joining block 47 obtained in step (G). Process (
H) is a step in which a plurality of composite magnetic heads are obtained by cutting the core to have a required core width T shown by a dotted line centering on the track width. In some cases, it is cut at an angle of azimuth. In this way, a narrow track composite magnetic head core having a structure as shown in FIG. 8(i), the magnetic tape sliding surface of which is shown, is obtained. By winding a coil around this, the composite magnetic head of the present invention can be obtained.

[Embodiment 2] FIGS. 5(a) and 5(b) are a perspective view and a plan view showing the structure of a composite magnetic head in another embodiment of the present invention. Generally speaking, the cut groove is formed only on the front part of the magnetic head core, that is, on the side facing the recording medium, and the rear part is in contact with the entire width of the ferrite core. In this way, even for a magnetic head having a narrow track, an efficient narrow track head can be obtained because the magnetic resistance at the rear part does not increase. The numerals appended to each are the same as in FIG. 4. In addition,
The filling groove shape of the reinforcing materials 33, 33' can be selected from various shapes depending on the shape of the grinding wheel.
, 35' have a structure that widens as the distance from the working gap increases, and a predetermined azimuth loss is generated to reduce crosstalk. Further, it is desirable that the ferrite protrusion be brought close to the working gap portion, since eddy current loss near the working gap surface can be reduced. Furthermore, Figure 5
In the case of a magnetic head having the structure shown in FIG. 1, it is preferable to provide a cutout groove in the joint portion at the rear of the core and fill it with reinforcing material 36.

In the composite magnetic head of Example 1, when manufacturing the same, a groove is formed in the gap forming surface through to the rear part of the core (the side opposite to the surface facing the magnetic recording medium), as shown in FIG. 8(A). This allows grooves to be formed on large blocks at once.
It can be divided into small blocks later, and in this respect it is suitable for mass production, but if the track width becomes narrow, the contact area of the rear core portion becomes narrow and the magnetic resistance at the rear of the core becomes high, which is undesirable. Furthermore, even if the track widths are matched at the front (the side facing the magnetic recording medium), misalignment will occur at the rear, and if the track width is less than 10 microns, there may be almost no contact between the magnetic parts. . This problem is solved in the composite magnetic head of Example 2 by forming cutout grooves 42, 42' in the ridges of the high magnetic permeability ferrite block 40, as shown in FIG. Thereafter, a magnetic head is obtained by the steps starting from FIG. 8(c). The completed head is a composite magnetic head as shown in FIG.

Other examples of various groove shapes and processing methods are shown in FIGS. 10(a) to 10(d). FIG. 10(a) shows grooves 42, 42' machined using a forming grindstone with a V-shaped tip. In this case, if the angle θ of the groove is too large, the protrusion 4
As the angle θ' of 8 becomes larger, the variation in the dimensional accuracy for obtaining the track width t as shown in FIG. 8(e) by polishing after forming the metal magnetic film becomes larger. On the other hand, if the angle θ is made small, the protrusion becomes mechanically weak in the case of a narrow track, and may be chipped during machining. Therefore, the protrusion angle θ' is preferably about 45 to 90 degrees. However, it can be manufactured outside this range and is not limited thereto. On the other hand, as shown in FIG. 10(b), only the tip of the protrusion 48 can be made rectangular, but in this case, it is preferable that the tip of the protrusion does not have a flat portion. This processing method may be performed by machining, or may be performed by processing the corners as shown by dotted lines 49 by reverse sputtering before depositing the metal magnetic film.

[0048] In the above-described groove machining, protrusions can be formed at one time by using two stacked grindstones 50 as shown in FIG. 10(c). Moreover, as shown in FIG. 10(d), if a multi-wire saw is used, it is possible to process a large number of blocks at the same time. In this case, the groove 42 is formed in a U-shape. Furthermore, laser processing and photo-etching techniques can be applied, and these techniques may be used in combination.

[Embodiment 3] FIG. 6 shows a plan view of a composite magnetic head in still another embodiment of the present invention. This figure shows an enlarged view of the magnetic tape sliding surface. Ferrite protrusions 35, 35 that serve as the core of the metal magnetic films 30, 30'
Even if the bonding surface at the tip of ' is formed parallel to the working gap surface, if the width a of the ferrite protrusion is less than 1/2 of the track width t, the contour effect in reproduction will be less than 0.5 dB, which will hardly be a problem. Not. At this time, it is more preferable to process the tip of the ferrite protrusion so that it is not flat.

[Embodiment 4] FIG. 7 is a schematic plan view of a composite magnetic head in another embodiment of the present invention, showing an enlarged view of the magnetic tape sliding surface. In the magnetic head of this embodiment, the working gap portion 32 is composed of metal magnetic films 30, 30' and ferrites 35, 35', and the width of the metal magnetic film constituting the track width t is 2 times the width b of the ferrite. It will be more than doubled. In this way, in the case of recording, the metal magnetic part having a high saturation magnetic flux density is dominant, and in the case of reproduction in particular, the ferrite part with high magnetic permeability is dominant, so that the overall reproduction efficiency is improved. Note that if the width of the ferrite is wide, recording at the center of the track will be insufficient and the reproduction output will deteriorate.

[0051]

[Effects of the Invention] As explained above, the composite magnetic head according to the present invention has a metallic body with a high saturation magnetic flux density that can sufficiently record even on a recording medium with a high coercive force, a high magnetic permeability, and high wear resistance. In combination with ferrite, etc., they compensate for each other's shortcomings, resulting in a narrow track magnetic head with excellent recording and reproducing characteristics.

[0052] In each drawing showing the magnetic head,
Although illustration of the coil is omitted, it is assumed that the coil is installed.

As described above, the composite magnetic head of the present invention has a structure in which (1) eddy current loss can be reduced compared to conventional composite magnetic heads.

(2) The contour effect can be ignored.

(3) There are structural advantages such as a large contact area between the metal magnetic film and the ferrite, and excellent head performance can be obtained.

(4) Since one metal magnetic film is used twice in the working gap portion, the time for depositing the metal magnetic film is halved, which facilitates mass production.

(5) There is no need to process the side surface of the metal magnetic film with a grindstone when determining the track width, and there are no problems such as chipping, burrs, or peeling of the film at the processed part.

(6) Since it is filled with a non-magnetic reinforcing member, the medium sliding surface becomes flat, the medium is not damaged, and the strength of the entire head is guaranteed. Also, there is no uneven wear.

(7) Mass production is easy and the structure is suitable for mass production.

There are great advantages such as:

[Brief explanation of the drawing]

[Fig. 1] Perspective view and top view of a conventional composite magnetic head

[Fig. 2] Perspective view and top view of a conventional composite magnetic head

[Fig. 3] Perspective view of another conventional composite magnetic head

[Figure 4]
(a) and (b) are a perspective view of a composite magnetic head and an enlarged view of a magnetic tape sliding surface in an embodiment of the present invention.

FIGS. 5(a) and 5(b) are a perspective view and an enlarged view of a magnetic tape sliding surface of a composite magnetic head in another embodiment of the present invention;

FIG. 6 is an enlarged view of the magnetic tape sliding surface of a composite magnetic head in still another embodiment of the present invention.

FIG. 7 is an enlarged view of the magnetic tape sliding surface of a composite magnetic head in still another embodiment of the present invention.

[Fig. 8] (A) to (R) are explanatory diagrams of the manufacturing process of the composite magnetic head of the present invention.

FIG. 9 is a perspective view of a processed ferrite block in manufacturing the composite magnetic head of the present invention.

FIGS. 10(a), (b), and (d) are plan views of processed ferrite blocks used in various embodiments of the present invention, and (c) is a plan view of a grindstone for processing ferrite blocks used in the production of the present invention. Cross section

[Fig. 11] (A) to (E) are explanatory diagrams, perspective views, and plan views of each step of a conventional method for manufacturing a composite magnetic head.

[Explanation of symbols]

30, 30'... Metal magnetic film, 31, 31'... High magnetic permeability ferrite block, 32... Operating gap, 33, 33
'...Nonmagnetic filler, 34...Coil winding window, 35, 35'
...Ferrite protrusion, 40...High magnetic permeability ferrite block, 41...Gap forming side surface, 42, 42'...Groove, 4
4...Metal magnetic film, 45...Nonmagnetic material, 47...Joining block, 50...Whetstone.

Claims (19)

[Claims] Claims: 1. Two base blocks, a kerf formed in the base block from the medium facing surface side to the opposite side thereof to leave a block having a width narrower than a track width, and a kerf covering the kerf. A magnetic gap formed by the deposited magnetic film and the magnetic material deposited on the narrow block portion facing each other, and a coil winding window present by cutting a part of the magnetic film. Composite magnetic head. 2. The composite magnetic head according to claim 1, wherein the magnetic material is an amorphous alloy. 3. The composite magnetic head according to claim 1, wherein the magnetic material is crystalline. 4. The composite magnetic head according to claim 1, wherein the nonmagnetic material is at least one of glass, ceramic, and resin. 5. The composite magnetic head according to claim 3, wherein the melting point of the non-magnetic material is lower than the crystallization temperature of the amorphous magnetic material. 6. The composite magnetic head according to claim 1, wherein the working gap forming surface is made of only the magnetic material. 7. The composite magnetic head according to claim 6, wherein the width of the narrow block is less than 1/2 of the track width. 8. A composite magnetic head according to claim 6, wherein the width of said narrow block is approximately zero. 9. The composite magnetic head according to claim 1, wherein the thickness of the magnetic material is 1/2 or less of the track width. 10. The thickness of the magnetic material is approximately 1 of the track width.
9. The composite magnetic head according to claim 8, wherein: /2. 11. Claim 1, wherein the working gap forming surface is comprised of the magnetic material and the base block.
6. The composite magnetic head according to any one of 5 to 5. 12. The composite magnetic head according to claim 11, wherein the width of the magnetic material in the track width direction on the working gap forming surface is at least twice the width of the narrow block. 13. The composite magnetic head according to claim 1, wherein the base block is made of Mn--Zn ferrite or Ni--Zn ferrite. 14. The composite magnetic head according to claim 13, wherein a portion of the magnetic material is removed to form a portion or all of the coil winding groove. 15. The magnetic material is Fe-Si alloy, Fe-A
2. The composite magnetic head according to claim 1, wherein the magnetic head is an l-Si alloy, a Ni-Fe alloy, or a high permeability amorphous alloy. 16. The composite magnetic head according to claim 1, wherein the magnetic material has a multilayer structure. 17. The composite magnetic head according to claim 16, wherein the magnetic material has a multilayer structure in which non-magnetic materials are alternately laminated. 18. The non-magnetic material is SiO2 or Al2O3.
The composite magnetic head according to claim 17, characterized in that: 19. The composite magnetic head according to claim 16, wherein the multilayer structure is formed by a sputtering method.