JPH031307A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To allow magnetic recording and reproducing of a high surface recording density with an azimuth recording system by setting the direction where grooves for coil windings are formed at a prescribed direction. CONSTITUTION:The grooves 11 for coil windings to be provided on core block half bodies 1 of the magnetic head are moved and worked in the direction to provide the disposition where the slopes of magnetic core layers 6 juxtaposed in the half bodies 1 are always inclined downward from the surface on the side forming the grooves 11 and the side opposite to the advancing side of a grinding wheel at all times and in the same direction27 as the direction of the rotating tangent component at the lowermost point of the rotary grinding wheel 7 when the above-mentioned grooves 11 are formed across the magnetic core layers 6 juxtaposed to the block half bodies 1. The formation of the boat- shaped grooves for the coil windings are, therefore, not formed by the difference in the azimuth. The shorting of the soft magnetic metallic thin films to each other beyond insulating thin films by the ductility of the metal is thus obviated. The magnetic recording and reproducing of a wide frequency range at the high surface recording density with the azimuth recording system are possible in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a method of manufacturing a magnetic head. More specifically, we are using an insulating thin film to create a thin film of high saturation magnetic flux density metal and soft magnetic material, which enables highly efficient recording and reproducing over a wide range of tens of megahertz and fully utilizes the performance of high coercive force media. The present invention relates to a method of manufacturing a rotary magnetic head having a magnetic core having a laminated structure.

(B) Conventional Invention FIG. 3 shows an example of a conventional method for manufacturing a magnetic head whose magnetic core is a laminate of a soft magnetic metal thin film and an insulating thin film. This is a magnetic head whose magnetic core 8 is a laminate 6 of a soft magnetic metal thin film and an insulating thin film formed on one slope of a plurality of parallel V-shaped grooves 11 processed on the surface of a non-magnetic substrate 10. This is the manufacturing method of No. 9.

A plurality of parallel V-shaped grooves 11 are formed on the surface of the non-magnetic substrate 10 by a rotating grindstone (not shown) (Figure (a)).
■Groove 1! is formed by the self-shading effect of the V-groove apex 12 using a thin film forming method such as electron beam evaporation in which the flying direction of particles contributing to vapor deposition is constant. A laminated body 6 is formed by alternately forming a soft magnetic metal thin film and an insulating thin film only on one side of the slope.
((b) in the same figure). Here, examples of the soft magnetic metal include FeAlSi alloy (trademark Sendust) and FeNi alloy (Permalloy), and examples of the insulating thin film include S
io 1. Examples include Alto 3. In addition, the thickness of the soft magnetic metal layer has an appropriate value depending on the frequency band in which the magnetic head operates, the magnetic permeability and resistivity of the soft magnetic metal, and the thickness of the insulating thin film is determined by the thickness of the soft magnetic metal thin film. The thickness should be such that it does not occur (-0.1 to 0.2 μm within the film).

Then, in order to protect the laminate 6 from the glass 13 for later filling the V-groove Z and to improve wetting with the glass 13, a thin film of metal such as Cr or Ta is formed with a thickness of 0.1-1 μm. (Illustration omitted).

After that, the V-groove II is filled with glass 13, and the excess glass 13 is removed to form a magnetic head core base material 14 (see figure (C). The magnetic head core base material 14 is cut in the direction perpendicular to the V-groove. Then, a pair of magnetic head core halves L and D are formed (FIG. 2(d); for the sake of simplicity, the explanation will be given assuming that a pair of magnetic head core halves L and B are formed from the magnetic head core base material 14. In reality, a larger number of magnetic head core halves 1 are combined into one magnetic head core mother tt14.
formed from. ), V of this magnetic core half 1 Bi
After forming a boat-shaped groove 2 for coil winding on the side 3 where the groove il was formed using a grindstone, and forming an outer groove 15 for coil winding on the opposite side ((e) in the same figure), the boat-shaped groove 2 was machined. After precision drilling the side surface 3 and forming a thin film of non-magnetic material that will form the gap of the magnetic head on the polished surface 3 (not shown), the magnetic head core half [,! The laminated body 6 of the soft magnetic metal thin film and the insulating thin film are aligned and fixed so that they face each other, and heated to melt the glass 13 embedded in the V-groove 11, forming a pair of magnetic hepto cores. half body 1
．． 1' is welded to form a magnetic head hole 16 including a plurality of magnetic gap portions (FIG. 2(r)). After this, the surface 17 on the side that will become the medium sliding surface is ground into a cylindrical shape,
After performing processing to regulate the width of the medium sliding surface as necessary, the magnetic head 9 is divided into respective magnetic heads 9 in consideration of the azimuth (FIG. 3(g)). Figure 4 shows the obtained magnetic head 9.
FIG.

Figure 5 shows a conventional laminate 6 of a soft magnetic metal thin film and an insulating thin film.
Another example of the manufacturing method of the magnetic head 9 using the magnetic core 8 as shown in FIG. This is a method for manufacturing a magnetic head 9 in which a magnetic core 8 is a laminate 6 of a soft magnetic metal thin film and an insulating thin film formed on the surface of a plate-shaped nonmagnetic substrate 10.

A laminated body 6 is formed by alternately forming soft magnetic metal thin films and insulating thin films on the surface of the plate-shaped non-conductive substrate 10 using a thin film forming method such as electron beam evaporation or sputtering (see FIG.
)). The composition of these materials and their respective thicknesses are as described above. Furthermore, a metal thin film of Cr, Ta, etc. is formed (not shown) to protect the laminate 6 and to improve wetting with the glass, thereby forming a vapor-deposited substrate 18 serving as one unit.

Next, a plurality of vapor-deposited substrates 18 are laminated and welded with glass to form a magnetic rad core base material 14 (FIG. 1(b), for simplicity, the laminate 6 is drawn in three locations. (glass not shown).

At this time, the glass is applied by sputtering, screen printing, or the like.

Next, the magnetic head core base material 14 is cut at a plane having an angle that takes into account the azimuth of the resulting magnetic head 9 to form the magnetic head core half body 1 (see FIG. Therefore, it is assumed that two pairs of magnetic rad core halves (2) are formed from the magnetic rad core base material 14.)

After that, processing of the coil winding boat-shaped groove 2 and outer groove 15, polishing of the surface 3 on the side where the boat-shaped groove was formed, which will be the surface facing the gap, and formation of a non-magnetic thin film that will become a spacer (not shown) are carried out as described above. The method is similar to the conventional manufacturing method No. 1 ((d) in the same figure).

Next, the pair of magnetic helad core halves [, ■° are aligned and fixed so that the laminated bodies 6 of the soft magnetic metal thin film and the insulating thin film face each other, and Insert the glass rod 19 into the window section shown at 20 in the figure.
Heat the glass rod 1 with the side indicated by facing downward.
9 is melted and a pair of magnetic head core halves 1 and 1 are welded to form a magnetic head bar 16 including a plurality of magnetic gaps.

Thereafter, according to the manufacturing method described above, the magnetic head par 16 is cut to obtain a plurality of magnetic heads 9 (FIG. 4(f)). FIG. 6 is a perspective view of the obtained magnetic head 9.

(c) Problems to be Solved by the Invention According to the conventional manufacturing method described above, the magnetic head 9 was obtained in the intended shape in terms of appearance, but it had the following performance problems.

That is, when recording and reproducing adjacent tracks using magnetic heads having different azimuths in order to increase the areal recording density, there are differences in the characteristics of the magnetic heads having different azimuths.

Specifically, this characteristic difference is the difference between the frequency characteristic of impedance, which can be called the static characteristic of the magnetic core, and the frequency characteristic of the reproduced output, which can be called dynamic characteristic. A typical example of these differences is shown in FIG. The diagram shows the frequency characteristics of the inductance of the magnetic header. Here, FIG. 8 shows the magnetic head 9 on the recording medium sliding surface! Azimuth + (same figure (a), (c)) and - (same figure (b), (d) when viewed from 7)
)) showed the difference in direction. As can be seen from FIG. 7 above, the attenuation associated with an increase in the frequency of the inductance is larger in the azimuth range of 10 than in the - range. In addition, the attenuation was larger when the azimuth was set to 10 than when the playback output was set to -.

As mentioned above, since there is no difference in appearance except for the different azimuths, these differences were considered to be differences in the frequency characteristics of the magnetic cores 8.

Here, we will touch on the meaning of using the laminate 6 of the soft magnetic metal thin film 4 and the insulating thin film 5 as the magnetic core 8. To form a magnetic head 9 with the same thickness as the magnetic core 8, the insulating thin film 5 is sandwiched. If the layered structure is not used, the magnetic head 9
This is a means to solve the problem that when the magnetic core 8 is driven at a high frequency, the entire thickness of the magnetic core 8 does not operate effectively due to eddy currents, that is, the frequency characteristics of the magnetic core 8 are impaired.

From this point, the difference in characteristics due to the difference in azimuth is the difference between the magnetic core 8
This is thought to be due to factors that inhibit the effectiveness of the layered structure.

On the other hand, in the azimuth direction, the inductance and reproduction output attenuation are small, and the same tendency is exhibited no matter where the material is taken from the substrate of the deposited laminate 6 to form the magnetic head 9. It can be seen that the separation between the respective soft magnetic metal thin films 4 within the stacked body 6 formed by the thin film manufacturing means has been achieved.

Therefore, when we destroyed the magnetic head 9 and searched for the part where the separation between the laminated soft magnetic metal thin M4 was found to be insufficient, we found that the azimuth + A clear difference was observed between the magnetic heads. That is, in azimuth +, the soft magnetic metal thin films were electrically and magnetically short-circuited by overcoming the insulating thin film due to the ductility of the metal.

As mentioned above, the window 21 provided for the coil winding is
It is formed by machining the boat-shaped groove 2 in units of magnetic core halves 1, but during this machining, due to the difference in azimuth, the magnetic helad core halves! Because the arrangement of the laminate 6 is different within the
It was thought that the ductility of the metal makes the difference in whether or not the soft magnetic metal thin films cross over the insulating thin film and short-circuit with each other.

This difference is due to the fact that when forming the coil winding boat-shaped groove 2, the grinding wheel 7 must be placed in the same direction in the processing device as shown in FIG.
This is because the parallelism between the reference side (indicated by 28 in the figure) and the feeding direction during processing of the magnetic head core half 1 was ensured, and the boat-shaped groove 2 for coil winding was formed at a predetermined position. According to this working method, depending on the azimuth difference of the magnetic head 9, FIGS.
Differences as shown in d) may occur.

That is, assuming that the grinding wheel 7 rotates clockwise and the magnetic held core half 1 in which the boat-shaped groove 2 is formed moves from right to left in the figure, at an azimuth of 10, a lamination of a soft magnetic metal thin film and an insulating thin film is formed. The body 6 is located on the left-sloping surface 24, whereas in the azimuth (a) and (c) of the figure, the laminated body 6 of the soft magnetic metal thin film and the insulating thin film is located on the right-sloping surface 24 in the figure. It is located on the slope 23 ((b), (d) of the same figure). In other words, when the azimuth is ten, the laminated body 6 of the soft magnetic metal thin film and the insulating thin film is located on the gap facing surface 3 within the magnetic helad core half l.
On the other hand, in the azimuth direction, the gap is inclined from the gap facing surface 3 to the side opposite to the side where the grindstone 7 enters.

This difference in arrangement, combined with the rotating direction of the grinding wheel 7 and the moving direction of the magnetic rad core half 1, determines whether or not the soft magnetic metal thin films will short-circuit together over the insulating thin film due to the ductility of the metal. It was thought that there would be a difference.

This invention has been made in view of the above circumstances, and provides a magnetic head that is capable of magnetic recording and reproducing at a high areal recording density using an anomous recording method by setting the direction in which the coil winding grooves are formed in a predetermined direction. The purpose is to provide a manufacturing method.

(d) Means for Solving the Problems Thus, according to the present invention, a large number of magnetic core layers each made of a laminate of a soft magnetic metal thin film and an insulating thin film are arranged in inclined rows at predetermined intervals in a nonmagnetic substrate. After forming grooves for coil winding on the magnetic head core block halves having sloped cross sections of the magnetic core layers on the side surfaces of the substrate, the two block halves are placed on the side surfaces of each block half. In the method for manufacturing a magnetic head in which a magnetic head chip is obtained by joining the magnetic core layers so that the inclined cross sections thereof are linearly connected and then dividing the magnetic core layers into each linear magnetic core layer, the step of forming the coil winding grooves. However, the magnetic head core block half is moved under the rotary whetstone so that the direction of the rotational tangential component at the lowest point of the rotary whetstone is the same as the moving direction of the block half. Therefore, when the wave grooves are formed in some places in the magnetic core layer arranged in the block half,
The block half is moved in such a direction that the inclined surfaces of the magnetic core layers arranged in a row in the half are arranged to be on the side opposite to the grinding wheel entry side from the surface on which the grooves are formed and are inclined downward. A method of manufacturing a magnetic head is provided.

(E) Effect According to the present invention, when the coil winding groove provided in the magnetic head core block half is formed by cutting out the magnetic core layer arranged in rows in the block half, always The inclined surfaces of the magnetic core layers arranged in a row in the half body are arranged in such a way that they are located on the opposite side of the grinding wheel entry side from the side where the grooves are formed and are inclined downward, and at the lowest point of the rotating grinding wheel. It will be moved and processed in the same direction as the direction of the rotational tangential component.

The present invention will be described in detail below with reference to Examples, but the present invention is not limited thereby.

(f) Example An embodiment of the present invention is shown in FIGS. 1(a) and 1(b).

This is a magnetism that uses a laminate 6 of a soft magnetic metal thin film and an insulating thin film as a magnetic core 8, which is formed on one slope of a plurality of parallel V-shaped grooves 11 processed on the surface of a non-magnetic substrate 10. This is the case with the manufacturing method of Rad9.

FIG. 1(a) shows the case of azimuth +.

The grindstone 7 for forming the boat-shaped groove 2 rotates clockwise (this direction is the same in all subsequent examples).

The grindstone 7 is installed in the processing device with the inclined portion 25 (corresponding to the apex portion of the coil winding window of the magnetic head) in the direction 26 in the figure.

The magnetic head core block half 1 is fixed to a processing device with the surface 3 facing the gap facing upward, and the fixed magnetic head core block half 1 is moved in the direction 27 in the figure by the feeding mechanism of the processing device. It is sent to contact the grindstone 7, and the boat-shaped groove 2 is machined. At this time, the edge 28 on the side that should become the front gap of the magnetic head 9, which is half of the magnetic head core block, is oriented as shown in the figure, and the laminate 6 of the soft magnetic metal thin film and the insulating thin film (i.e., the magnetic core layer) is
V groove! It is located on the surface 23 of the slope (2) opposite to the grindstone entrance side. That is, the laminated body 6 of the soft magnetic metal thin film and the insulating thin film is inclined within the magnetic head core block half 1 from the gap facing surface 3 toward the side opposite to the grindstone entrance side.

FIG. 1(b) shows the case of azimuth.

In this case, the grindstone 7 is installed in the processing device in the opposite direction to that shown in FIG. Also, at this time, the edge 2 on the side that should become the front gap of the magnetic head core block half 1
8 is oriented as shown in the figure, which is opposite to the case of azimuth +. Therefore, as in the case of azimuth +, the laminated body 6 of the soft magnetic metal thin film and the insulating thin film is located on the surface 23 of the slope of the V-groove 11 on the side opposite to the grinding wheel entrance side.

FIG. 2 shows the frequency characteristics of the inductance of a magnetic head manufactured by the manufacturing method of the present invention. It can be seen that the frequency characteristics are similar regardless of the anomas. The frequency characteristics of the playback output are now the same.

Another embodiment of the present invention is shown in FIGS. 1(c) and 1(d). This is the case in the method of manufacturing a magnetic head 9 in which the magnetic core 8 is a laminate 6 of a soft magnetic metal thin film and an insulating thin film formed on the surface of a plate-shaped non-magnetic substrate ITO'. In this case, in the same way as in the manufacturing method described above, regardless of the azimuth, the laminated body 6 of the soft magnetic metal thin film and the insulating thin film is placed in the magnetic hepto core block half 1 from the gap facing surface 3 to the grinding wheel entry side. It was located on the surface 23 inclined to the opposite side, and the characteristics of the obtained magnetic head were not dependent on the ± of the azimuth.

(G) Effects of the Invention According to the method of the present invention, when forming the boat-shaped groove 2 for coil winding, the soft magnetic metal thin film 5 is crossed over the insulating thin film 5 due to the ductility of the metal regardless of the difference in azimuth. Since there is no short circuit between the two azimuths, it is possible to sufficiently obtain the effect of making the magnetic helad core a laminate of a soft magnetic gold 1+ thin film and an insulating thin film in both azimuths. This enables wide-band magnetic recording and reproduction with high areal recording density using the anomalous recording method.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the arrangement and movement direction of the grindstone and magnetic head core block halves when forming a boat-shaped groove for coil winding in the method of the present invention, and FIG. A diagram showing the characteristics of the obtained magnetic head, FIG. 3 is a diagram for explaining the conventional method of manufacturing a magnetic head, FIG. 4 is a perspective view of the magnetic head obtained by the method shown in FIG. 3, and FIG. 6 is a perspective view of a magnetic head obtained by the method shown in FIG. 5, and FIG. 7 is a diagram illustrating a conventional magnetic head manufacturing method. FIG. 8 is a diagram showing the azimuth direction of the magnetic core layer in the magnetic head. FIGS. 9 and 10 are diagrams showing the grinding wheel used to form the conventional boat-shaped groove for coil winding. FIG. 3 is a diagram for explaining the arrangement and direction of magnetic head core block halves. 7...Whetstone. l... Half magnetic head core block, 2... Boat-shaped groove for coil winding, 3... Gap opposing surface, 4... Soft magnetic metal thin film, 5... Insulating thin film, 6...・Laminated body, number of stomach circumferences [MHz] (b) (C) (d) Box flute diagram closed 1°! lvI Mi, LIE (MH2I Nodding Question (a) *10 Leap

Claims (1)

[Scope of Claims] 1. A large number of magnetic core layers each made of a laminate of soft magnetic metal thin films and insulating thin films are arranged in rows at predetermined intervals in an inclined manner in a non-magnetic substrate, and these are arranged on the side surface of the substrate. After forming coil winding grooves on the magnetic head core block halves having a magnetic core layer having a sloped cross section, two of the block halves were formed so that the slope cross section of the magnetic core layer on the side surface of each block half was straight. In the manufacturing method of a magnetic head, in which a magnetic head chip is obtained by joining each linear magnetic core layer so as to connect to each other, the magnetic head chip is obtained by dividing the linear magnetic core layer into each linear magnetic core layer. The core block half is machined by moving in such a way that the direction of the rotational tangential component at the lowest point of the rotary grindstone and the moving direction of the block half are the same, and the groove is When formed across the magnetic core layers arranged in a block half, the inclined surface of the magnetic core layers arranged in the half is opposite from the grinding wheel entry side from the side where the groove is formed. A method of manufacturing a magnetic head, characterized in that the half block is moved in a direction such that it is arranged sideways and downwardly inclined.