JPH0622044B2 - Manufacturing method of core for composite type magnetic head - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method of manufacturing a core for a composite magnetic head, and more particularly to a magnetic head suitable for recording / reproducing a high frequency signal such as a VTR, especially for a high coercive force medium. The present invention relates to a method for advantageously manufacturing a core for a composite magnetic head, which provides a suitable composite magnetic head.

(Background Art) In a high density magnetic recording / reproducing apparatus, it is known that it is advantageous to increase the coercive force: H _C of the magnetic recording medium, but in order to record information on the magnetic recording medium having a high coercive force. Needs to increase the leakage magnetic field from the magnetic head.
However, at present, the ferrite material used for the core of the magnetic head has a saturation magnetic flux density: B _S of 40.
Since it is from 00 to 5000 gauss, there is a limit to the strength of the recording magnetic field that can be obtained, and when the coercive force of the magnetic recording medium exceeds 1000 Oersted, there is a drawback that recording is insufficient.

On the other hand, a magnetic head using a crystalline alloy such as an Fe-Al-Si alloy (sendust) Ni-Fe alloy (permalloy) or an amorphous alloy, which is a general term for metallic magnetic materials, generally has a saturation flux higher than that of a ferrite material. It has excellent characteristics of high density and low sliding noise. However, in a commonly used track width (10 μm or more), the effective magnetic permeability in the video frequency region is lower than that of ferrite due to the eddy current loss, and the reproduction efficiency is lowered. Also, it is several steps inferior to ferrite in terms of wear resistance.

Therefore, in order to solve the above problems, a core for a composite magnetic head has been proposed in which ferrite and a metal magnetic material are combined and the advantages of both are utilized.

For example, as shown in FIG. 1 which is an inclined view of one such core for a composite magnetic head, the core portions 1, 1 '
Is composed of a ferrite having a high magnetic permeability, and the magnetic gap 5, which is the main part of the recording action, is composed of metal magnetic materials 2 and 2'formed by physical vapor deposition such as sputtering. Is proposed. In this magnetic head core, the track width is narrowed for high density recording, and notch grooves 7, 7 for narrowing the track width are provided on both sides in the vicinity of the magnetic gap 5, and a nonmagnetic material for reinforcement is provided there. 3 is filled. In addition, 6 is a window (hole) for coil winding. FIG. 2 shows a plan view of the recording medium facing surface of such a conventional magnetic head core.
It has been recognized that there is a drawback that the recording / reproducing characteristics are impaired by the fact that the coupling boundaries 4 and 4 ′ between the ferrite cores 1 and 1 ′ and the metal magnetic materials 2 and 2 ′ act as pseudo gaps. In particular, the coupling boundaries 4, 4'and the magnetic gap 5
When the lines are parallel to each other, a considerable amount of signals are picked up at the boundary, and there is an inherent problem that the so-called contour effect becomes severe, which causes undulations in the frequency characteristics of the reproduction output.

As another composite type magnetic head core, a structure as shown in FIG. 3 is also known. In the magnetic head core shown in FIG. 3, a metal magnetic material 12 having a high saturation magnetic flux density is formed on a non-magnetic substrate 11 by sputtering or physical vapor deposition such as vacuum vapor deposition to have a film thickness equal to the track width. After a non-magnetic material 11 'is adhered thereon by a glass thin film, the gap abutting surface is divided into two halves, and then a coil winding window 13 is formed, and a predetermined non-magnetic film is formed on the gap abutting surface. It is manufactured by applying the above-mentioned method and bonding through it. However, such a magnetic head core inherently has the following problems. That is, when the track width is as large as 20 μm or more, the metal magnetic material 12 has a poor high-frequency characteristic due to eddy current loss in a single-layer film, so it is necessary to have a multi-layer structure with a non-magnetic material interposed therebetween. Compared to the magnetic head core shown in the figure, the area for forming the metal magnetic material 12 per core is large, which is unproductive, and the track width is determined by the film thickness of the metal magnetic material 12. Therefore, there is an inherent problem that the film thickness accuracy in the batch is strictly required, and the assembling of the magnetic head core is very complicated.

Further, JP-A-58-155513 proposes a core for a composite magnetic head having a structure as shown in FIGS. 4 (a) and 4 (b). This magnetic head core is
Two high-permeability ferrite blocks 21 each having a protrusion whose cross-sectional shape on the surface facing the magnetic recording medium protrudes,
Magnetic bodies 22, 22 'having a higher saturation magnetic flux density than ferrite are adhered to at least both side surfaces of the protruding portion of 21',
At the tip of the protrusion, via the magnetic gap 23,
The magnetic bodies 22 and 22 'face each other, and the width of the ferrite at the tip of the protrusion is smaller than the track width. Reference numerals 25 and 26 respectively denote a non-magnetic embedding material and a coil winding window.

In the case of such a structure, the ferrites 21 and 2
Boundary coupling portions 24, 2 between the 1'and the metallic magnetic materials 22, 22 '
Since 4'is largely inclined with respect to the magnetic gap 23, there is an advantage that there is no contour effect of reproduction output as in the magnetic head core as shown in FIG. In addition to being weak, it is difficult to obtain a desired shape, and the track width easily changes due to the polishing amount of the surface on which the magnetic gap 23 is formed. Therefore, it is difficult to obtain the accuracy of the track width. It is inherent.

Further, in JP-A-61-265714, JP-A-61-273706 and the like, a joint portion between ferrite and a magnetic material is used as a core for a composite type magnetic head formed by combining ferrite and a metal magnetic material. The uneven part is provided on the
It is clarified that the positions of the concavo-convex portions on the left and right core portions are arranged at asymmetrical positions, or at least one minute gap extending toward the magnetic gap portion is formed in the magnetic material. Is the core for such a magnetic head,
It is manufactured as follows.

That is, a predetermined ferrite block is provided with a resist film formed by forming slits in stripes, and etching is performed to form a corrugated uneven surface, and then a corrugated uneven surface is formed. After forming a magnetic layer made of a metallic magnetic material and polishing the surface to a flat surface, a plurality of grooves defining the track width were formed in parallel with each other, and then a groove for coil winding was formed. After that, the two ferrite blocks are combined and joined together to form an integral combination, and then this ferrite block combination is cut at a predetermined position to obtain the desired core for the composite magnetic head. A manufacturing method that sequentially cuts out is clarified.

However, in such a method of manufacturing a core for a composite type magnetic head, a non-magnetic material (glass) is poured into the track width defining groove after the formation of the magnetic layer made of a metal magnetic material. There is a problem like this. That is, when the metal magnetic material is amorphous synthetic or permalloy alloy, such magnetic material is
When it is heated above ℃, its magnetic properties deteriorate, and especially in the case of amorphous alloy, it will be greatly deteriorated due to crystallization, so glass must be poured into the track width defining groove below 500 ℃. No, therefore a low melting glass must be used. Thus, in the case of a low melting point glass, not only is there a difficulty in abrasion resistance when the magnetic recording medium is slid, but it is also weak in strength and has a drawback in that chips such as grinding and cutting occur. .

Further, in the case where the metal magnetic material is sendust, there is no problem that the magnetic characteristics are deteriorated by the pouring of the high melting point glass as described above, but when heated to 500 ° C. or higher, for example, 700 to 800 ° C. or higher, Because of the large difference in thermal expansion coefficient with ferrite (Sendust: 150 × 10 ^-7 ,
Ferrite: 110-120 × 10 ^-7 ), the internal stress of Sendust becomes large during glass fusion, and the material of Sendust itself is not sticky, is brittle and adheres to the corrugated surface of ferrite. This causes problems such as cracking or easy peeling during or after grinding or cutting.

In any case, the method for manufacturing the composite magnetic head core according to the method of pouring the nonmagnetic material (glass) into the track width defining groove after forming the magnetic film made of the metal magnetic material is practically used. However, there are some drawbacks, and it was not industrially advantageous.

(Object of the Invention) Here, the present invention has been made in view of the above circumstances, and an object of the present invention is to solve the problems in the conventional core for a composite type magnetic head and the manufacturing method thereof. The present invention provides a core for a magnetic head showing excellent recording / reproducing characteristics even for a high coercive force recording medium, and an easy manufacturing method therefor. Particularly, it is easy to improve the track width accuracy, and lithography technology and etching are used. By using a technique to make the coupling boundary surface between the ferrite and the metal magnetic material oblique with respect to the magnetic gap, it is possible to advantageously manufacture a core for a composite magnetic head having no contour effect in reproduction output.

(Structure of the Invention) In order to achieve such an object, the present invention forms an annular magnetic path by abutting the first and second ferrite blocks, and at the abutting portions of the ferrite blocks, a predetermined gap is formed. In a method of manufacturing a core for a magnetic head using a combination body having a magnetic gap, (a) a track is formed on at least a magnetic gap forming portion of a butting surface of at least one of the two ferrite blocks with respect to the other ferrite block. A first step of forming at least two mutually parallel grooves defining a width in a direction parallel to the abutting surface and orthogonal to the magnetic gap; and (b) forming the track width defining groove. Apply a predetermined non-magnetic material to the abutting surface of the ferrite block, and embed the non-magnetic material in the track width defining groove. A second step of: (c) a third step of removing an unnecessary portion of the non-magnetic material applied to the abutting surface of the ferrite block to expose the track portion sandwiched by the track width defining groove; d) After forming a predetermined resist film on the abutting surface of the ferrite block so that a part of the track portion is exposed as at least one exposed portion extending in the formation direction of the track width defining groove with a predetermined width. A fourth step of etching the track portion through the exposed portion to form an uneven surface, and (e) a fifth step of depositing a predetermined metal magnetic material on the etched abutting surface of the ferrite block. And (f) removing a predetermined thickness portion of the abutting surface of the ferrite block coated with the metal magnetic material, and depositing the metal magnetic material deposited layer formed on the uneven surface of the track portion. A sixth step of exposing the non-magnetic material embedded in the track width defining groove while leaving the first and the second steps of (g) prior to or after the sixth step. A seventh step of forming a groove for coil winding on at least one butt surface of the second ferrite block; and (h) the first and second ferrite blocks after the first to seventh steps. An eighth step of forming a non-magnetic layer having a predetermined thickness on at least the magnetic gap forming portion of the abutting surface of at least one of them, (i)
The ninth step in which the magnetic gap forming portions of the abutting surfaces of the first and second ferrite blocks, which have completed the eighth step, are opposed to each other, and are bonded to each other, and (j) the bonding and integrated first step A tenth step of cutting the first and second ferrite block combinations at predetermined positions to obtain at least one composite magnetic head core. Is the gist.

According to the embodiment of the method of the present invention,
In the fourth step, a plurality of exposed portions,
A curved or bent surface that forms a part of the waveform in the width direction of the track portion by being formed on the track portion at a predetermined interval and etching the track portion through the plurality of exposed portions. Are formed, so that a surface inclined with respect to the magnetic gap is formed.

Further, in the method of the present invention, prior to the fifth step, on the surface of at least the exposed track portion of the abutting surface of the ferrite block, the ferrite that constitutes the track portion and the ferrite that constitutes the track portion are deposited. The operation of forming a glass layer that is brought into close contact with the metal magnetic material described above is performed as necessary.

(Specific Configurations and Examples of the Invention) By the way, in the present invention, the first and second ferrite blocks that provide the combination used to manufacture the intended core for the composite magnetic head are conventionally formed. The high magnetic permeability ferrite material of is used as a long plate-shaped block having a predetermined thickness so that a plurality of magnetic head cores can be manufactured, and their abutting forms an annular magnetic path. It can be configured. In addition, as the ferrite block having high magnetic permeability, Mn
A single crystal or a polycrystal such as —Zn ferrite or Ni—Zn ferrite, or a composite thereof is used. In particular, when the single crystal is used, (100),
Crystal planes such as (110), (311) and (332) are advantageously selected as gap facing surfaces (ferrite block butt surfaces).

And in the present invention, first, in the first step,
At least two grooves which are parallel to each other and define a track width in at least a magnetic gap forming portion of the abutting surface of at least one of the two ferrite blocks with respect to the other ferrite block are parallel to the abutting surface and have a magnetic gap. Will be formed in orthogonal directions.

By the way, FIG. 5 (a) shows an example in which a plurality of grooves 32 defining the track width are formed in the magnetic gap forming portion on the gap facing surface (butting surface) 31a of the predetermined high magnetic permeability ferrite block 31. As shown in FIG. 5 (a), the track width defining groove is formed only at the ridge (magnetic gap forming portion) of the ferrite block 31, and as shown in FIG. 5 (b). It does not matter if the groove 32 'is formed so as to extend to the rear portion of the core (the portion opposite to the magnetic recording medium facing surface 31b). The groove shapes of the track width defining grooves 32 and 32 'are appropriately selected and provided, for example, in the shape as shown in FIGS. 6A and 6B. 6B shows a groove shape as shown in FIG. 6A having a straight line portion perpendicular to the gap facing surface 31a even if the amount of polishing is varied. It is more suitable than the groove shape.

Then, in this way, in the ferrite block 31 provided with the track width defining groove 32, as shown in FIG. 7, as a second step, the gap facing surface 31a in which the track width defining groove 32 is formed is formed. Predetermined non-magnetic material 3
3 is applied, so that the non-magnetic material 33 is also embedded and filled in the track width defining groove 32. As the non-magnetic material 33, glass, a ceramic-based inorganic adhesive, a hard resin, or the like is used, but glass is suitable in terms of stability such as running property of the magnetic recording medium.

Then, after the nonmagnetic material 33 is embedded in the track width defining groove 32 in this way, at least the unnecessary nonmagnetic material 33 portion on the gap forming surface 31a of the ferrite block 31 is removed to define the track width defining area. The track portion sandwiched by the grooves 32, 32 is exposed (third step). To remove the unnecessary portion of the non-magnetic material 33, generally, a method of grinding and removing with a grindstone is adopted, and such a removing operation removes a predetermined thickness portion of the gap facing surface 31a of the ferrite block 31. . By such a removing operation, as shown in FIG. 8, the ferrite block 31 in which the non-magnetic material 33 is embedded only in the track width defining groove 32 is obtained.

In the fourth step, a ferrite block 31 having a predetermined non-magnetic material 33 embedded in the track width defining groove 32 is formed.
On the other hand, as shown in FIG. 9, a predetermined resist film 34 is formed on the gap facing surface 31a where the track portion is exposed, leaving a part of the track portion. That is,
A resist film 34 is formed on the gap facing surface 31a of the ferrite 31 so that a part of the track portion is exposed as at least one exposed portion (35) extending in the formation direction of the track width defining groove 32 with a predetermined width. It is.

The patterning of the resist film 34 is performed with ultraviolet light, X-rays, electron beams or the like. The pattern of the resist film 34 is, as shown in FIG. 10A, a thin slit 3 having a width of about 1 to 3 μm in the center of the track portion.
No. 5 is inserted, as shown in FIG. 10 (b), two such thin slits 35 are inserted, or as shown in FIG. 10 (c), a resist film is formed in the central portion. A shape in which narrow slit-shaped exposed portions (35) are formed at both ends in the width direction of the track portion, except for 34, is preferably adopted. Particularly, when the width of the track portion is as large as 50 μm or more, for example, it is desirable that the number of the slits 35 is at least two and the slits 35 are arranged in stripes at a predetermined interval. In the case where the track width is large and the number of slits is small, if the entire track width is to be etched, the etching amount in the depth direction increases and the required thickness of the metal magnetic material increases, which is unproductive. To solve this problem, if the slit width is increased, the slope of the etched ferrite surface with respect to the gap is decreased, and the effect of improving the contour effect is decreased.

Then, the ferrite block 31 on which the predetermined resist film 34 is formed is subjected to a known electrolytic etching process or chemical etching process. As a result, the exposed surface of the track portion which is not covered with the resist film 34, in other words, the track portion portion corresponding to the slit 35 of the resist film 34 is etched through the slit 35, and shown in FIG. As described above, the surface of the track portion becomes the uneven surface 36. As this etching condition, a condition in which the etching ratio of ferrite to the non-magnetic material 33 embedded in the track width defining groove 32 is extremely large is selected. Then, after this etching, the resist film 34 is removed. As a result, the uneven surface 36 etched into the shape shown in the enlarged view of FIG.
The track portion having is exposed. Regarding the surface shape of the exposed track portion, as shown in FIG.
(B) and (c) correspond to the formation forms of the resist film 34 in FIGS. 10 (a), (b), and (c), respectively, and in any shape, with respect to the magnetic gap. As the inclined surface shape, in other words, in the width direction of the track portion, it is formed as a curved surface or a bent surface forming a part of the waveform.

Then, as shown in FIG. 13, the ferrite block 31 subjected to the etching treatment is covered with a metal magnetic material 37 having a saturation magnetic flux density higher than that of ferrite by sputtering or the like on the entire surface 31a facing the gap. Dressed up (fifth step). The metallic magnetic material 37 includes Fe-Si (Si: 6.5% by weight) and Fe-Al-.
There are known crystalline alloys typified by Si alloys (Sendust), Ni-Fe alloys (Permalloy), and the like, while amorphous alloys are also known metals typified by, for example, Fe-Co-Si-B system. -Metalloid alloys, Co-Zr,
Well-known metal-metal alloys such as Co-Zr-Nb are used. When using Fe-Si, Fe-Al-Si alloys, etc., it is well known that addition of 5 wt% or less of elements such as Cr, Ti, Ta, etc. is added to improve corrosion resistance. It is done appropriately. In addition, vacuum deposition, ion plating,
Although it is possible to use CVD, plating, or the like, the sputtering method is preferably adopted because of large compositional variations and the like and the adherends being limited.

Prior to the deposition of the metal magnetic material 37, the uneven surface 3 of at least the track portion of the ferrite block 31.
6, a glass layer, for example, several tens to 10 as an intermediate layer.
It is possible to further improve the adhesiveness of the layer of the metal magnetic material by applying the layer with a thickness of about 0Å. Further, if at least one element of Fe, Ni, Co and the like is used for the intermediate layer, it is advantageous in terms of adhesion. When these magnetic materials are used as the intermediate layer, the thickness is 10
It should be less than 00Å. In addition, due to the presence of these intermediate layers,
Although the pseudo gap increases and the contour effect is a concern, it does not matter if the interface of the etched track portion is sufficiently inclined with respect to the gap. The presence of this intermediate glass layer increases the reproduction output due to the pseudo gap, and there is a concern about the contour effect, but if the ferrite interface of the etched track portion is sufficiently inclined with respect to the gap, It's not that much of a problem.

Then, the ferrite block 31 to which the metal magnetic material 37 is adhered is subjected to normal cutting and polishing operations on the gap facing surface 31a, so that the metal magnetic material 37 adhered to the ferrite block 31 is removed. The unnecessary portion, the ferrite portion and a part of the non-magnetic material 33 are removed (sixth step). That is, by removing a predetermined thickness portion of the gap facing surface 31a of the ferrite block 31 to which the metal magnetic material 37 is adhered, it is formed on the uneven surface 36 of the track portion as shown in FIG. The nonmagnetic material 33 embedded in the track width defining groove 32 is exposed while leaving the adhered layer of the metal magnetic material 37 with a predetermined thickness.
The width of the track portion constituted by the remaining metal magnetic material layer and the ferrite portion is defined.

Further, prior to or after the sixth step, a coil winding groove 38 is formed on at least one of the two ferrite blocks 31, 31 ′ on the gap facing surface 31 a side. Although the first step to the sixth step are applied only to the ferrite block 31 here, the first step to the sixth step are similarly applied to the other ferrite block 31 '. Even if it is added, it does not matter at all, and particularly in the present invention, the above first to sixth steps are advantageously applied to the two ferrite blocks 31 and 31 ', respectively. Then, after that, the gap facing surfaces (31a) of the ferrite blocks 31, 31 'which are butted against each other are surface-polished to be finally finished, and as shown in FIG. Ferrite blocks 31, 31 'having

Then, a nonmagnetic material for forming a gap such as SiO ₂ or glass has a predetermined thickness at a gap forming portion of at least one gap facing finished surface 39 (39 ′) of the ferrite blocks 31, 31 ′ obtained in the seventh step. Is applied by sputtering to form a gap forming layer having a predetermined thickness (eighth step). At this time, when a crystalline alloy such as Fe—Si or Fe—Al—Si is used as the metal magnetic material 37, the temperature is raised to 500 ° C. or higher to simultaneously heat treat the metal magnetic material. Can Si
It is desirable to use O ₂ or a high melting point glass as the non-magnetic material for forming the gap, and in the case of using a Ni—Fe alloy or an amorphous alloy as the metal magnetic material,
It is desirable to use a low melting point glass that can be bonded and heat-treated at 400 ° C. to 450 ° C. as the nonmagnetic material for forming the gap.

Next, the two ferrite blocks 31 and 31 'obtained in the eighth step are aligned and opposed so that the gap facing finish surfaces 39 and 39' are aligned with each other, and the annular magnetic paths are aligned. And then by heating and pressurizing, they are bonded and integrated by a conventional method to form a ferrite block bonded body 40 as a combined body as shown in FIG. 16 (ninth step). In this case, the joining is performed by the track width defining groove 3
If the non-magnetic material 33 filled in 2 is glass, this is performed by joining this glass and glass as a non-magnetic material for forming a gap. Further, the combination can be joined by the following method. That is, as a non-magnetic material for forming a gap, a refractory oxide such as SiO ₂ or Al ₂ O ₃ is formed on the surface facing the gap, while a glass rod is formed in the coil winding groove and, if necessary, a rear groove. It is also possible to fuse the glass rods put in these grooves by inserting, heating, and pressing to join the pair of ferrite blocks. Regarding the glass to be inserted into this groove and melted, the joining temperature will be selected according to the type of the magnetic metal material, as described above.

Further, by cutting the ferrite block bonded body (combined body) 40 bonded in the ninth step so that the core width (T) shown by the dotted line in FIG. The target composite magnetic head cores are sequentially cut out, and at least one of them is obtained. Incidentally, when cutting out the core, a method of tilting by an azimuth angle and cutting the core may be used depending on the case.

The structure of the composite magnetic head core according to the present invention thus obtained is shown in FIG. 18 as a perspective view. This structure corresponds to the case of FIG. 5 (a) in which the track width defining groove 32 is formed only on the ridge portion of the ferrite block 31 in the first step, and FIG. 19 shows such a core for a magnetic head. The morphology of the main part as viewed from the surface facing the magnetic recording medium is shown. On the other hand, the structure of the magnetic head core shown in FIG. 20 corresponds to the structure of FIG. 5 (b) in which the track width defining groove 32 'is formed up to the rear part of the ferrite block 31 in the first step. Is. In these figures, 41 is a magnetic gap formed between the metal magnetic material layers 37 and 37 'of the left and right track portions.

As described above, the core of the composite magnetic head obtained according to the present invention is wound with a coil by using the hole 42 formed by the groove 38 for coil winding. Thus, the desired composite magnetic head is obtained.

The method of manufacturing the magnetic head core according to the present invention has been described above in detail based on the manufacturing example of the VTR magnetic head core. However, the present invention should be construed as being limited to the specific examples. It should be understood that the present invention is not limited to the above, and may be implemented in a form in which various changes, modifications, improvements, etc. are added based on the knowledge of those skilled in the art without departing from the spirit of the present invention. is there.

Further, the method for manufacturing the composite magnetic head core according to the present invention is not limited to the illustrated VTR head, and is applicable to the manufacture of cores for magnetic heads such as FDD heads, RDD heads, and DAT heads. Needless to say, it is applicable.

(Effects of the Invention) As is clear from the above description, the method for manufacturing the composite magnetic head core according to the present invention is: (a) The obtained composite magnetic head core has a main magnetic circuit as compared with the conventional one. Is composed of ferrite, and the metal magnetic material exists only near the magnetic gap, so it is a method that can reduce eddy current loss. (B) The coupling interface between the ferrite and the metal magnetic material is magnetic. Due to the concavo-convex structure that is oblique to the gap, the contour effect can be ignored, and even if a glass layer is provided as an intermediate layer between the ferrite and the metal magnetic material to improve adhesion, such contour effect is ignored. (C) A high-precision track width can be obtained by using the ratio of the etching rates of the non-magnetic material and the ferrite that are embedded in the groove for defining the track width in advance. It is possible to mass-produce a magnetic head core consisting of (d) and by using a combination of a lithography technique and a etching technique using a resistor, a large number of ferrite blocks can be etched simultaneously and in a uniform shape, which in turn leads to uniform head characteristics. The magnetic head core can be mass-produced. (E) Since a nonmagnetic material is poured into the track width defining groove in advance and a magnetic film made of a metallic magnetic material is formed, wear resistance and processing There are no problems such as chipping,
High melting point glass can be used, especially when using amorphous alloy or permalloy alloy as the metal magnetic material, there is no thermal deterioration, while when sendust is used, cracks occur in the subsequent processing steps. Since there is no problem such as peeling, industrial production of the magnetic head core can be advantageously carried out, and there are a number of great advantages.

[Brief description of drawings]

1 and 2 are a perspective view and a top view showing an example of a conventional composite type magnetic head core, respectively, and FIG. 3 shows another example of a conventional composite type magnetic head core. 4 (a) and 4 (b) are respectively a perspective view and a top view showing still another example of the conventional composite type magnetic head core. 5 to 20 are explanatory views of each step according to one embodiment of the present invention, and FIGS. 5A and 5B show a ferrite block having different track width defining grooves. 6A and 6B are schematic cross-sectional views showing different cross-sectional shapes of the track width defining groove, and FIG. 7 is a perspective view of a main part of the ferrite block after completion of the second step. FIG. 8 is a perspective view of the ferrite block showing a state where the third step is finished, FIG. 9 is a perspective view of the ferrite block showing a state where the resist film is formed in the fourth step, FIGS. 10 (a), (b). ) And (c) are perspective views of a main part of a ferrite block provided with resist films of different forms, FIG. 11 is a perspective view of the ferrite block showing a state after etching in the fourth step, and FIG. ), (B) and FIG. 13C is a perspective view of a main portion showing an example in which the shape of the uneven surface of the track portion formed based on the different slit shapes of the resist film is different, and FIG. 13 is a perspective view of the ferrite block subjected to the fifth step. 14 is a perspective view of the ferrite block subjected to the sixth step, FIG. 15 is a perspective view of the ferrite block subjected to the seventh step, and FIG. 16 is two ferrites in the ninth step. FIG. 17 is a perspective view of a combination body in which blocks are integrated, FIG. 17 is a top view of the combination body for explaining a cutting position for obtaining one composite magnetic head core in the tenth step, FIG. 18 and FIG. 19 is a perspective view and a top view showing an example of a composite magnetic head core obtained according to the process of the present invention, and FIG. 20 is another example of a composite magnetic head core obtained according to the present invention. Is a diagram corresponding to FIG. 18 showing. 31, 31 ': Ferrite block 31a: Gap facing surface 32, 32': Track width defining groove 33, 33 ': Nonmagnetic embedding material 34: Resist film, 35: Slit 36: Concavo-convex surface, 37, 37': Metal magnetic Material 38: Groove for coil winding 39: Finished surface facing the gap 40: Ferrite block bonded body 41: Magnetic gap

Claims (3)

[Claims] 1. A magnetic head using a combination body in which a first and a second ferrite block are butted against each other to form an annular magnetic path, and a magnetic gap having a predetermined gap is formed at the butted portion of these ferrite blocks. In the method for manufacturing a core for use, at least two grooves parallel to each other that define a track width are provided in the abutting surface at least at a magnetic gap forming portion of the abutting surface of at least one of the two ferrite blocks with respect to the other ferrite block. The first step of forming in the parallel direction and in the direction orthogonal to the magnetic gap, and applying a predetermined non-magnetic material to the abutting surface of the ferrite block in which the track width defining groove is formed, thereby defining the track width The second step of embedding the non-magnetic material in the groove, and the non-magnetic material applied to the abutting surface of the ferrite block. A third step of removing an unnecessary portion of the elastic material to expose the track portion sandwiched by the track width defining grooves, and a part of the track portion extends in the track width defining groove forming direction with a predetermined width. A fourth step of forming a predetermined resist film on the abutting surface of the ferrite block so as to be exposed as at least one exposed portion, and then etching the track portion through the exposed portion to form an uneven surface. A fifth step of depositing a predetermined metal magnetic material on the etched abutting surface of the ferrite block, and removing a predetermined thickness portion of the abutting surface of the ferrite block coated with the metal magnetic material, Exposing a non-magnetic material embedded in the track width defining groove while leaving an adhered layer of the metal magnetic material formed on the uneven surface of the track portion with a predetermined thickness. Prior to or after the sixth step, a seventh step of forming a groove for coil winding on the butt surface of at least one of the first and second ferrite blocks, An eighth step of forming a non-magnetic layer of a predetermined thickness on at least a magnetic gap forming portion of the abutting surface of at least one of the first and second ferrite blocks after the first to seventh steps, Eighth step is completed, the magnetic gap forming portions of the abutting surfaces of the first and second ferrite blocks are opposed to each other, and are joined together to form a ninth step; A tenth step of cutting the ferrite block combination at a predetermined position to obtain at least one core for a composite magnetic head, the method for manufacturing a core for a composite magnetic head. 2. In the fourth step, a plurality of the exposed portions are formed on the track portion at predetermined intervals, and the track portion is etched through the plurality of exposed portions, The manufacturing method according to claim 1, wherein a curved or bent surface forming a part of the corrugation is formed in the width direction of the track portion. 3. Prior to the fifth step, on the surface of at least the exposed track portion of the abutting surface of the ferrite block, the ferrite constituting the track portion and the metal magnetic material adhered thereon are formed. The manufacturing method according to claim 1 or 2, wherein a glass layer that adheres to and is formed.