JPS63164010A - Manufacture of magnetic head - Google Patents

Abstract

PURPOSE:To prevent noise due to a pseudo gap by forming a prescribed form of magnetic metallic film to a magnetic block and bonding the blocks by a low melting point glass and cutting off the result so as to suppress the diffusion reaction between the magnetic substances. CONSTITUTION:The high melting point glass 32 is filled as the 1st nonmagnetic member to the track width regulating slot of an oxide magnetic block 30 and the result is polished, a part is removed to form a magnetic metallic film 34 to the removed part. Then the other block 30 having a winding slot 35 of the similar structure is formed. Then the both are butted and they are bonded by the magnetic metallic film 34 being the 2nd nonmagnetic material, and cut off into a prescribed size to finish chips. As a result, after the magnetic metallic film 34 is formed, a high temperature process is not required, the diffusion reaction between magnetic substances is suppressed and a magnetic head without production of noise due to a pseudo gap is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a magnetic head, in particular a magnetic head in which the vicinity of the magnetic gap is formed of a magnetic metal film, and most of the magnetic core is made of an oxide magnetic material. The present invention relates to a method of manufacturing a magnetic head.

[Conventional technology]

In recent years, with the demand for high-density recording in magnetic recording and reproducing devices such as VTRs and video floppies, so-called metal tapes, metal sheets, etc., which have a large coercive force Hc, have come to be used as recording media. A head material for a recording/reproducing magnetic head compatible with a magnetic recording medium having such a large coercive force is required to have a high saturation magnetic flux density Bs and a high magnetic permeability.

On the other hand, for example, ferrite materials, which have conventionally been widely used as magnetic head materials, have a problem of low Bs. Therefore, it has been proposed to use a bulk alloy material such as Sendust (Fe-AI!-5i alloy) having a high Bs for the magnetic core. However, when a metallic magnetic material is used as the core material,
Eddy current loss becomes a problem, and high magnetic permeability in the high frequency region cannot be obtained.

For this reason, studies were conducted to use thin film formation technology to create a multilayer film by alternately laminating metal magnetic materials and insulators as a core material. As a result, as shown in FIG. 3, a non-magnetic guard material 11. Sendust et al. and S.
Multilayer ferromagnetic metal thin film made of iO□ etc. 10. 10'
A magnetic head has been proposed in which a track and a magnetic gap 12 are formed by these multilayer films 10' and 10'.

Although this type of magnetic head is capable of narrowing the track, the ferromagnetic film 10°10' must be formed on the ceramic substrate II, 11' to a film thickness corresponding to the track width. Thin film forming techniques have a limit to their film growth rate, and it takes a lot of time to produce the thin film. In addition, each magnetic head formed flat in this way is
Productivity is low because it has to be manufactured by matching pieces.

Therefore, as shown in FIG. 4, most of the half-holes 20.20' of the pair of magnetic cores are formed of an oxide magnetic material such as Mn-Zn ferrite, and the magnetic gap forming surface is formed by sputtering or other methods. A magnetic head has been proposed in which a magnetic metal film 21.21' of sendust or the like is formed using vacuum thin film fabrication technology, and a pair of core halves thus obtained are joined with high melting point glass 24.24'. There is. In this type of magnetic head, since the vicinity of the magnetic gap 25 is composed of a ferromagnetic metal thin film 21°21' having a high saturation magnetic flux density, it is suitable for magnetic recording media having high coercive force such as metal tapes. Accordingly, it is possible to exhibit sufficient recording and reproducing characteristics. In addition, the sliding surface of the tape is mostly filled with magnetic oxides such as ferrite, which gives it excellent wear resistance.

However, in the magnetic head shown in FIG. 4 described above, since the magnetic metal film 21.21', which is a different material, is formed on the ferrite core material, the boundary 23.23' is a pseudo gap. This has become a major problem, as it acts as a negative influence on electromagnetic conversion characteristics. In particular, this magnetic head has ferromagnetic metal films 21, 21'
After forming a pair of magnetic cores, a pair of magnetic cores are formed. 20'
High melting point glass 24. 24', the ferrite and sendust of each magnetic material are exposed to high temperature for a long time, and the boundaries 23. Diffusion reactions tend to occur at 23'. Therefore, the magnetic discontinuity at this boundary 23, 23' becomes remarkable, acts as a pseudo gap, and has the drawback that noise is likely to occur due to the so-called contour effect. Here, in order to solve the above-mentioned drawbacks, it has been considered to use so-called low-melting glass to lower the temperature during fusion bonding.

[Problem that the invention seeks to solve]

Low melting point glass has problems with abrasion resistance, water resistance, environmental resistance, etc., and as in this case, thick (
Since the low melting point glass is exposed, there is a problem in that the reliability of the magnetic head is significantly reduced.

As mentioned above, the magnetic head shown in Figure 3, which was proposed as a magnetic head compatible with high coercive force media, has the problem of poor productivity, and the magnetic head proposed to solve this problem As shown in Figure 4, in magnetic heads, the effect of the pseudo gap becomes noticeable due to heat treatment during manufacturing.
There is a problem in that it is difficult to obtain sufficient recording and reproducing characteristics.

Therefore, the present invention was proposed to solve these problems, and even if the interface between the oxide magnetic material and the magnetic metal film is parallel to the magnetic gap on the tape sliding surface, It is an object of the present invention to provide a method for manufacturing a magnetic head that efficiently manufactures a highly reliable magnetic head without the boundary portion acting as a pseudo gap.

[Means for solving problems]

For this purpose, the method for manufacturing a magnetic head according to the present invention includes the steps of forming track width regulating grooves at a predetermined pitch on one end of an oxide magnetic material block, and applying a first non-magnetic material to the regulating grooves. a step of filling, and a step of surface grinding the end surface after the filling to a surface where the oxide magnetic material is exposed;
a step of removing at least a portion of the oxide magnetic material exposed on the ground surface; a step of disposing a magnetic metal film in the removed portion; and a step of removing at least one of the blocks on which the metal film is disposed. The method includes the steps of butting the blocks so that they face each other, joining with a second non-magnetic material having a lower melting point than the first non-magnetic material, and cutting the joined block to have a predetermined head width.

[For production]

According to the manufacturing method described above, first, the track width regulating groove is filled with a high melting point non-magnetic material, a magnetic metal thin film is deposited near the magnetic gap forming part, a pair of magnetic core blocks is manufactured, and then a low melting point non-magnetic material is filled. Since the magnetic metal films of these magnetic core blocks are abutted and joined using a non-magnetic material having a melting point, the magnetic core blocks can be manufactured without exposing them to high temperatures after the magnetic metal films are formed. Therefore, the mutual diffusion reaction at the boundary between the oxide magnetic material and the magnetic metal film is suppressed, and the non-magnetic material exposed on the sliding surface of the magnetic recording medium has a high melting point, ensuring reliability. Furthermore, the surface on the side of the oxide magnetic material that forms the bonding boundary of each of the magnetic materials is an etched surface, and the process-altered layer caused by the processing history such as cutting, polishing, and grinding has been removed. This reduces the magnetic resistance of the magnetic path, resulting in improved electromagnetic conversion efficiency.

(Embodiment) An embodiment of the method for manufacturing a magnetic head according to the present invention will now be described in detail with reference to FIGS. 1(A) to 1(I).

First, as shown in FIG. 1(A), a groove 31 regulating the track width is provided on the upper surface of a substrate 30 made of an oxide magnetic material such as Mn-Zn ferrite, and the width tw of the peak portion is set to the track width. A plurality of them are formed in parallel with a predetermined pitch so that These track width regulating grooves 31 have V-shaped tips.
It is obtained by grinding to a predetermined depth using a rotary grindstone or the like shaped into a letter shape.

Next, as shown in FIG. 1(B), a high melting point glass 32, which is a first non-magnetic material, is placed in the track width regulating groove 31 at 60°C.
The track width regulating groove 31 is filled by pouring in N2 atmosphere at a temperature of 0° C. to 800° C. for about 30 minutes to 60 minutes. Thereafter, as shown in FIG. 1(C), the high melting point glass 3
The portion formed other than the track width regulating groove No. 2 is removed by surface grinding or the like, and the surface is further surface lapped using diamond abrasive grains.

Next, the oxide magnetic material 3° is etched between the high melting point glass 32 and the oxide magnetic material 30 such as Mn-Zn ferrite. For example, the oxide magnetic material 3o is Mn-Zn
If it is ferrite, an etchant that selectively etches it, such as an aqueous phosphoric acid solution, is used. In this way, the oxide magnetic material 3o is etched, as shown in Fig. 1(D).
Track grooves 33 are formed as shown in FIG. Here, in this embodiment, the depth of this track groove 33 is 20 to 30 μm.
It was etched to a certain extent.

Next, as shown in FIG. 1E, a Co--Zr--Nb based magnetic metal thin film 34 is deposited on the track groove 33 and the upper surface of the high melting point glass 32 by sputtering or the like. Here, the material used for the magnetic metal thin film 34 is a so-called amorphous alloy (for example, Fe).

An alloy consisting of one or more elements of Ni and Co and one or more elements of P, B, and Si, or an alloy consisting of these as the main component and containing AI, Ge, Be, Sn, In, Mo, w
, Ti.

(alloy containing Mn, Cr, Zr, Hf, Nb, etc.) or Fe-Al-5i alloy, Fe-A n -
5i-Ni alloy, Fe-Aj! type alloy, Fe-3i type alloy, Fe-Ni type alloy, etc. can be used, and the film forming methods thereof include evaporation, sputtering, and ion blating.

A vacuum thin film forming method such as ion beam sputtering is used. In this embodiment, the thickness of the magnetic metal thin film 34 was set to 10 μm to 20 μm.

Next, as shown in FIG. 1(F), the magnetic metal thin film 34
A core half block 80 is obtained by surface grinding. This surface grinding process is continued until the high melting point glass 32 appears, that is, until the magnetic metal thin film 34 remains only on the oxide magnetic material 30. This processed surface corresponds to the surface forming the magnetic gap.

Here, a pair of core half blocks obtained by the above-mentioned process is prepared, and a winding groove 35 as shown in FIG. 1(G) is formed in one of the core half blocks. Obtain block 90.

Next, the pair of core half blocks 80. The surfaces corresponding to the gap surfaces 90 are mirror-polished, and a gap spacer 37 made of a non-magnetic material such as Si02 is formed on at least one of each surface to a thickness that provides a predetermined gap length.

Then, as shown in FIG. 1(H), these pair of core half blocks 80.90 are butted together so that the magnetic metal thin films 34 are aligned with each other with high precision, and these core half blocks 80.90 are placed in the second core half block 80.90. Using the melting point of the low melting point glass 36 as a non-magnetic material, it is placed in a static magnetic field in the direction shown by the arrow X in the figure, or in a rotating magnetic field in a plane whose normal direction is the direction shown by the arrow X in the figure. ,350°C~400
Bonding at a temperature of °C.

Finally, cut at the positions of dashed-dotted lines A and A' to cut out the head chip. Of course, a plurality of head chips can be obtained by similar cutting. By processing the medium sliding surface of the head chip thus obtained into a predetermined radius of curvature, a magnetic herad core as shown in FIG. 1(1) is completed. Furthermore, a magnetic head is obtained by winding this core.

In the magnetic head obtained in this way, although the boundaries a and a' of the magnetic gear are formed, the effect of these boundaries a and a' as a pseudo gap can be made very small. did it. The reproduction output of the pseudo gaps a and a' of the magnetic head manufactured according to this example is suppressed to -40 to -30 dB compared to that of the main gap, and is sufficiently compatible with analog recording and reproduction. . Further, since the tape sliding surface of this magnetic head is composed of high melting point glass 32, magnetic metal film 34, and oxide magnetic material, wear resistance etc. are improved and reliability is excellent.

By the way, the present invention is not limited to the above-described embodiment, and may be a magnetic head in which high melting point glass is formed only on the front gap side, for example. In other words, Figure 2 (
As shown in A), a groove 40 having a substantially V-shaped tip is used as a track width regulating groove to regulate the track width only in the portion corresponding to the front gap forming surface on the upper surface of the substrate 30 made of an oxide magnetic material. Form multiple lines in parallel. This second figure (
The substrate shown in A) corresponds to the substrate shown in FIG. 1(A) in the above embodiment. Next, the previous example was applied (similar process).

The method first includes a filling process of the high melting point glass 32, a surface grinding process for partially removing the high melting point glass 32, a process of forming track grooves by etching the oxide magnetic material, and a process of depositing the magnetic metal film 34. Then, the magnetic metal film 34 deposited on the high-melting point glass is removed by surface grinding, and as shown in FIG.
A pair of core blocks shown in B) are manufactured. Next, in the same manner as in the previous embodiment, the core block 50 provided with the winding grooves of the core block 60 was fused and bonded using low melting point glass, a plurality of head chips were cut out, and the tape sliding surface was cut out. The magnetic head shown in FIG. 2(C) may be manufactured by cylindrical grinding to a predetermined curvature. In the magnetic head shown in FIG. 2(C), the high melting point glass 32 is formed only on the front gap side, but in addition to the same effect as the previous embodiment, the magnetic metal films 34 on the back gap side are opposite to each other. This has the effect of increasing the area, lowering the magnetic resistance in the back gap, and improving the electromagnetic conversion efficiency of the magnetic head.

Further, in the process of etching the oxide magnetic material 30 to form track grooves, the high melting point glass 32 may be protected from the etching solution with a resist material such as photoresist or cyst. By doing so, it becomes possible to use an etching liquid that also corrodes the high melting point glass 32. Further, this track groove machining may be performed using a dry etching process such as ion milling or acid dip ion milling.

〔Effect of the invention〕

As explained above, according to the method for manufacturing a magnetic head of the present invention, there is no high-temperature processing step after forming the magnetic metal film (therefore, diffusion reactions between the magnetic materials can be suppressed, A magnetic head without the problem of noise caused by pseudo gaps can be obtained.Furthermore, it is possible to use amorphous alloys, which crystallize at high temperatures and deteriorate their properties, without impairing their properties. The sliding surface is made of a material with excellent wear resistance, such as a magnetic oxide material, a magnetic metal film, and a nonmagnetic material with a high melting point, resulting in a highly reliable magnetic head.

In addition, the surface on the side of the oxide magnetic material that forms the bonding boundary between each two types of magnetic materials is an etched surface, and the processed damaged layer generated due to the processing history has been removed, and the boundary between the two types of magnetic materials is etched. This reduces the magnetic resistance at the gap, reduces the effect of a pseudo gap, and improves electromagnetic conversion efficiency.

[Brief explanation of the drawing]

FIGS. 1(A) to (+) are diagrams for explaining the manufacturing method of a magnetic head according to an embodiment of the present invention in the order of steps, and FIGS. 2(A) to (C) are diagrams showing other embodiments of the present invention. FIG. 3 is a perspective view showing an example of a conventional magnetic head; FIG. 4 is a perspective view showing another example of a conventional magnetic head. . In the figure, 30 is an oxide magnetic material block, 31 is a track width regulating groove, 32 is a high melting point glass as the first non-magnetic material, 3
4 is a magnetic metal film, 36 is a low melting point glass as a second non-magnetic material, and 37 is a gap spacer.

Claims (1)

[Claims] forming track width regulating grooves at a predetermined pitch on one end surface of the oxide magnetic material block; filling the regulating grooves with a first non-magnetic material; and after filling the end surface and the oxide magnetic material. a step of surface grinding to the exposed surface, a step of removing at least a part of the oxide magnetic material exposed on the ground surface, a step of disposing a magnetic metal film on the removed portion, and a step of disposing the metal film. a step of butting the blocks so that at least a portion of the metal films face each other and joining them with a second non-magnetic material having a lower melting point than the first non-magnetic material; and a step of joining the joined blocks to a predetermined head width. A method of manufacturing a magnetic head including a step of cutting it so that it becomes .