JPH0748246B2 - Method of manufacturing magnetic head - Google Patents

Description

The present invention relates to a method of manufacturing a magnetic head. More specifically, it is possible to record / reproduce in a wide band of several tens of megahertz at a high rate, and to fully utilize the performance of a high coercive force medium. 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 of manufacturing a magnetic head using a laminated body of a soft magnetic metal thin film and an insulating thin film as a magnetic core. This is a plurality of parallel Vs processed on the surface of the non-magnetic substrate 10.
This is a method of manufacturing a magnetic head 9 in which a laminated body 6 of a soft magnetic metal thin film and an insulating thin film formed on one side slope of a group of V-shaped grooves 11 is used as a magnetic core 8.

A plurality of parallel V-shaped grooves 11 are formed by a rotating grindstone (not shown) on the surface of the non-magnetic substrate 10 (FIG. 10A), and the direction of flight of particles contributing to vapor deposition such as electron beam vapor deposition is changed. By the self-shading effect of the V groove apex 12 by a constant thin film forming method, the soft magnetic metal thin film and the insulating thin film are alternately formed only on one of the slopes of the V groove 11 to form the laminated body 6 ( The same figure (b)). Examples of the soft magnetic metal include FeAlSi-based alloy (trademark Sendust) and FeNi-based alloy (permalloy), and examples of the insulating thin film include SiO ₂ and Al ₂ O ₃ . There is an appropriate value for the thickness of the soft magnetic metal layer depending on the frequency band in which the magnetic head operates, the magnetic permeability and the resistivity of the soft magnetic metal, and the thickness of the insulating thin film does not short-circuit between the soft magnetic metal thin films. Such a thickness (generally 0.1 to 0.2 μm) is used. Then, in order to protect the laminated body 6 from the glass 13 for filling the V groove 11 later and to improve the wettability with the glass 13, a thin film of metal such as Cr and Ta is formed with a thickness of 0.1 to 1 μm (illustration). Omitted).

After that, the V groove 11 is filled with glass 13 and the excess glass 13 is removed to form a magnetic head core base material 14 (FIG. 7C). The magnetic head core base material 14 is cut in a direction orthogonal to the V groove to form a pair of magnetic head core halves 1 and 1 '((d) in the figure, and for simplification of description, a pair of magnetic head core base materials 14 are separated from each other). The magnetic head core halves 1 and 1'will be described below. In reality, a larger number of magnetic head core halves 1 are formed from one magnetic head core base material 14.) 1'V groove 11
After machining the coil winding boat-shaped groove 2 on the side 3 on which the ridge is formed and the coil winding outer groove 15 on the opposite side (FIG. (E)), the side of the boat-shaped groove 2 machined After the surface 3 is precisely polished to form a thin film of a non-magnetic material that serves as a gap of the magnetic head on the polished surface 3 (not shown), it is insulative to the soft magnetic metal thin film in the magnetic head core halves 1 and 1 '. The thin film stacks 6 are aligned so that they are opposed to each other, fixed and heated to melt the glass 13 embedded in the V groove 11 and weld a pair of magnetic head core halves 1, 1 '. Magnetic head bar including multiple magnetic gap parts
16 is formed ((f) in the same figure). After that, the surface 17 on the side that becomes the medium sliding surface is ground into a cylindrical shape, and if necessary, the width of the medium sliding surface is regulated. It is divided into two parts (Fig. 4 (g)).
FIG. 4 is a perspective view of the obtained magnetic head 9.

FIG. 5 shows a conventional laminated body 6 of a soft magnetic metal thin film and an insulating thin film.
Another example of a method of manufacturing the magnetic head 9 having the magnetic core 8 will be described. This is a method of manufacturing a magnetic head 9 using a laminated body 6 of a soft magnetic metal thin film and an insulating thin film formed on the surface of a plate-shaped non-magnetic substrate 10 as a magnetic core 8. The surface of the plate-shaped non-magnetic substrate 10 Then, a soft magnetic metal thin film and an insulating thin film are alternately formed by a thin film forming method such as an electron beam vapor deposition method and a sputtering method to form a laminated body 6 (FIG. 9A). The material composition and the thickness of each are as described above. Further, a metal thin film of Cr, Ta or the like for protecting the laminated body 6 and for improving wettability with glass is formed (not shown) to form a vapor-deposited substrate 18 as one unit.

Next, a plurality of vapor-deposited substrates 18 are laminated and welded with glass to form a magnetic head core base material 14 (FIG. 2B), and for the sake of simplicity, the laminated body 6 is drawn in three places.
Glass is not shown). At this time, the glass is deposited by a sputtering method, a screen printing method or the like.

Next, the magnetic head core base material 14 is applied to the obtained magnetic head 9
The magnetic head core half body 1 is formed by cutting the magnetic head core half body 1 at a surface having an angle taking into consideration the azimuth of FIG. Was drawn as what forms.).

After that, the processing of the coil winding boat-shaped groove 2 and the outer groove 15, the polishing of the surface 3 on the side where the boat-shaped groove serving as the gap facing surface is formed, and the formation of the non-magnetic thin film serving as the spacer (not shown),
This is based on the first conventional manufacturing method (FIG. 3D).

Next, the pair of magnetic head core halves 1 and 1 ′ were aligned and fixed so that the laminates 6 of the soft magnetic metal thin film and the insulating thin film face each other, and then fixed, and formed by the boat-shaped groove 2. The glass rod 19 is inserted into the window portion and heated so that the surface indicated by 20 in the figure faces downward, the glass rod 19 is melted and the pair of magnetic head core halves 1, 1 ′ are welded to form a plurality of magnetic gaps. The included magnetic head bar 16 is formed ((e) in the same figure).

After that, the magnetic head bar 16 is cut to obtain a plurality of magnetic heads 9 in accordance with the above-described manufacturing method ((f) in the figure). Sixth
The figure is a perspective view of the obtained magnetic head 9.

(C) Problem to be Solved by the Invention According to the above-described conventional manufacturing method, the magnetic head 9 was obtained in an externally intended shape, but had the following performance problem.

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

Specifically, this characteristic difference is a difference between the frequency characteristic of the impedance, which is called the static characteristic of the magnetic core, and the frequency characteristic of the reproduction output, which is the dynamic characteristic. A typical example of these differences is shown in FIG. This figure shows the frequency characteristic of the inductance of the magnetic head. Here, FIG. 8 shows azimuths + ((a) and (c) in the figure) and-((b) and (d) in the figure) when the magnetic head 9 is viewed from the sliding surface 17 of the recording medium.
Showed the difference in direction. As can be seen from FIG. 7, the attenuation of the azimuth + as the frequency of the inductance increases is larger than that of −. Similarly, the playback output is azimuth +
Was larger than −.

As described above, there is no difference in appearance except for the difference in azimuth, so these differences were considered to be the frequency characteristic differences of the magnetic core 8.

Here, the meaning of using the laminated body 6 of the soft magnetic metal thin film 4 and the insulating thin film 5 as the magnetic core 8 will be described. The insulating thin film 5 is sandwiched to form the magnetic head 9 having the same magnetic core 8 thickness. Magnetic layer 9
Is a means for solving the problem that the entire thickness of the magnetic core 8 does not operate effectively due to the eddy current, that is, the frequency characteristic of the magnetic core 8 is impaired when driven at a high frequency.

From this point, the difference in characteristics due to the difference in azimuth is due to the magnetic core 8
It was considered that this was due to a factor that hinders the effect of forming a laminated structure.

On the other hand, in azimuth, the inductance and the attenuation of the reproduction output are small, and even if the magnetic head 9 is formed by using a material taken from any position on the substrate of the deposited laminated body 6, the same tendency is obtained. It can be considered that the separation between the respective soft magnetic metal thin films 4 in the laminated body 6 formed by the thin film forming means is achieved.

Then, the magnetic head 9 is destroyed and a portion where the separation between the laminated soft magnetic metal thin films 4 is recognized to be insufficient is inspected. As a result, the azimuth at the inner peripheral portion of the window 21 provided for the coil winding. A clear difference was observed between the + and-magnetic heads. In other words, 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 described above, the window 21 provided for the coil winding is formed by processing the boat-shaped groove 2 in the unit of the magnetic core half body 1. During this processing, the magnetic head core half is formed due to the difference in azimuth. It was considered that the difference in whether or not the soft magnetic metal thin films short-circuited over each other due to the ductility of the metal due to the disposition of the laminated body 6 in the body 1 would cross over the insulating thin film.

As a difference, the magnetic head core half 1 to be processed after the operation for forming the boat winding groove 2 for the coil winding and the direction in which the grindstone 7 is arranged in the processing device are constant as shown in FIG.
This is due to the fact that the side (indicated by 28 in the figure) serving as a reference and the feed direction during processing of the magnetic head core half body 1 are secured in parallel, and the boat winding groove 2 for coil winding is formed at a predetermined position. According to such a working method, a difference as shown in FIGS. 10 (a), (b) or (c), (d) may occur due to a difference in azimuth of the magnetic head 9.

That is, assuming that the grindstone 7 rotates clockwise and the magnetic head core half 1 in which the boat-shaped groove 2 is formed moves from right to left in the figure, in the case of azimuth +, a laminated body of a soft magnetic metal thin film and an insulating thin film 6 is located on the surface 24 which descends to the left ((a) and (c) in the same figure), the laminated body 6 of the soft magnetic metal thin film and the insulating thin film in the azimuth-indicates to the lower right in the figure. It is located on the slope 23 ((b) and (d) in the figure). In other words, in azimuth +, a laminated body 6 of a soft magnetic metal thin film and an insulating thin film is used.
Is inclined in the magnetic head core half 1 toward the side where the grindstone 7 enters from the gap facing surface 3, whereas in the azimuth, it is inclined toward the side opposite to the side where the grindstone 7 enters from the gap facing surface 3. There is.

Due to the balance of this disposition and the rotating direction of the grindstone 7 and the moving direction of the magnetic head core half 1, whether or not the soft magnetic metal thin films are short-circuited over the insulating thin film due to the ductility of the metal. Was thought to appear.

The present invention has been made in view of the above circumstances, and a magnetic head capable of magnetic recording / reproducing with high areal recording density by the azimuth recording method by setting the forming direction of the coil winding groove to a predetermined direction. It is intended to provide a manufacturing method.

(D) Means for Solving the Problems According to the present invention, therefore, a large number of magnetic core layers each composed of a laminated body of a soft magnetic metal thin film and an insulating thin film are arranged in rows in a non-magnetic substrate at a predetermined interval. And forming a coil winding groove on the side surface of the substrate, the magnetic head core block half having the inclined cross-section of these magnetic core layers, and then connecting the two block halves to the side surface of each block half. In the method of manufacturing a magnetic head, the magnetic core layers are joined so that the inclined cross-sections are linearly connected, and then the linear magnetic core layers are divided to obtain magnetic head chips. However, the magnetic head core block half body is processed under the rotary grindstone by moving so that the direction of the rotational tangent component at the lowest point of the rotary grindstone and the moving direction of the block half body are the same direction. And the groove is When formed across the magnetic core layer arranged in a row in the block half body, the inclined surface of the magnetic core layer arranged in a line in the half body, from the surface forming the groove and the grindstone entrance side There is provided a method of manufacturing a magnetic head, characterized in that the block half is moved in a direction in which it is arranged on the opposite side and is inclined downward.

(E) Action According to the present invention, when the coil winding groove provided in the magnetic head core block half body is formed across the magnetic core layers arranged in line in the block half body, The inclined surface of the magnetic core layer arranged in a row in the half body is on the opposite side of the groove forming side from the surface on which the groove is formed, and in the direction inclined downward, at the lowest point of the rotating grindstone. It is moved and processed in the same direction as the direction of the rotational tangent component.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

(F) Embodiment An embodiment of the present invention is shown in FIGS. 1 (a) and 1 (b). This is a plurality of parallel Vs processed on the surface of the non-magnetic substrate 10.
This is a case of a method of manufacturing a magnetic head 9 in which a laminated body 6 of a soft magnetic metal thin film and an insulating thin film formed on one side slope of a group of V-shaped grooves 11 is used as a magnetic core 8.

FIG. 1 (a) shows the case of azimuth +. The grindstone 7 for forming the boat-shaped groove 2 rotates in the clockwise direction (in the following examples, all have the same direction). Whetstone 7
Is installed in the processing apparatus with the inclined portion 25 (corresponding to the apex portion of the coil winding window of the magnetic head) in the direction of 26 in the drawing. The magnetic head core block half body 1 is fixed to the processing device with the surface 3 which faces the gap facing up, and the fixed magnetic head core block half body 1 is moved in the direction of 27 in the drawing by the feeding mechanism of the processing device. It is sent and contacts the grindstone 7, and the boat-shaped groove 2 is processed. At this time, the edge 28 of the magnetic head core block half 1 on the side to be the front gap of the magnetic head 9 is oriented as shown in the figure, and the laminated body 6 of the soft magnetic metal thin film and the insulating thin film (that is, the magnetic thin film). The core layer is a surface of the slope of the V groove 11 opposite to the grindstone entry side.
Located at 23. That is, the laminated body 6 of the soft magnetic metal thin film and the insulating thin film is inclined in the magnetic head core block half body 1 from the gap facing surface 3 to the side opposite to the grindstone entry 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 of FIG. At this time, the edge 28 of the magnetic head core block half body 1 on the side to be the front gap is oriented as shown in the figure, which is opposite to the case of azimuth +. Therefore, as in the case of azimuth +, the laminated layered body 6 of the soft magnetic metal thin film and the insulating thin film is located on the surface 23 of the V groove 11 on the side opposite to the grindstone entry side.

FIG. 2 shows the frequency characteristics of the inductance of the magnetic head manufactured by the manufacturing method of the present invention. It can be seen that the frequency characteristics are similar regardless of azimuth. The frequency characteristics of the reproduction output became similar.

FIGS. 1 (c) and 1 (d) show another embodiment of the present invention. This is the case of the method of manufacturing the magnetic head 9 in which the laminated body 6 of the soft magnetic metal thin film and the insulating thin film formed on the surface of the plate-shaped non-magnetic substrate 10 'is used as the magnetic core 8. Also in this case, similarly to the above-described manufacturing method, the laminated body 6 of the soft magnetic metal thin film and the insulating thin film is arranged in the magnetic head core block half body 1 from the gap facing surface 3 to the grindstone entry side regardless of the azimuth ±. It was located on the surface 23 inclined to the opposite side, and the characteristics of the obtained magnetic head did not depend on ± of azimuth.

(G) Effect of the Invention According to the method of the present invention, when forming the boat winding groove 2 for the coil winding, the soft magnetic metal thin film is overcome by overcoming the insulating thin film 5 due to the ductility of the metal regardless of the difference in azimuth. Is not short-circuited, the effect of forming the magnetic head core as a laminated body of a soft magnetic metal thin film and an insulating thin film can be sufficiently obtained with both ± azimuths. This enables wide band magnetic recording / reproduction with a high areal recording density by the azimuth recording method.

[Brief description of drawings]

FIG. 1 is a view for explaining the arrangement and direction of movement of a grindstone and a magnetic head core block half when forming a boat-shaped groove for coil winding in the method of the present invention, and FIG. The figure which shows the characteristic of the obtained magnetic head, FIG. 3 is a figure for demonstrating the manufacturing method of the conventional magnetic head, FIG. 4 is the perspective view of the magnetic head obtained by the method of FIG. 3, and FIG. Is a diagram for explaining a conventional method of manufacturing a magnetic head, FIG. 6 is a perspective view of a magnetic head obtained by the method of FIG. 5, and FIG. 7 is a characteristic of a magnetic head manufactured by the conventional method. And FIG. 8 are views for explaining the azimuth direction of the magnetic core layer in the magnetic head,
9 and 10 are views for explaining the arrangement and direction of the grindstone and the magnetic head core block half body when forming the boat-shaped groove for coil winding of the conventional example. 1 ... Magnetic head core block half body, 2 ... Boat winding groove for coil winding, 3 ... Gap facing surface, 4 ... Soft magnetic metal thin film, 5 ... Insulating thin film, 6 ... Laminated body, 7 ... … Whetstone.

Claims (1)

[Claims] 1. A non-magnetic substrate, in which a plurality of magnetic core layers each composed of a laminated body of a soft magnetic metal thin film and an insulating thin film are arranged in a row at a predetermined interval, and these magnetic cores are provided on a side surface of the substrate. After forming a coil winding groove in a magnetic head core block half having a layered cross-section, connect the two block halves in a straight line to the tilted cross-section of the magnetic core layer on the side surface of each block half. In the method for manufacturing a magnetic head, in which the magnetic head chips are obtained by dividing the magnetic core layers into linear magnetic core layers after bonding to each other, the step of forming the groove for coil winding includes The process comprises moving the body so that the direction of the rotational tangent component at the lowest point of the rotary grindstone and the moving direction of the block half body are the same, and the groove is the half block body. Across the magnetic core layer When formed by, the inclined surface of the magnetic core layer arranged in a row in the half body, in the direction of the arrangement that is inclined downward from the surface forming the groove on the side opposite to the grindstone entrance side,
A method of manufacturing a magnetic head, comprising moving the block half body.