JPH04195903A - Magnetic head - Google Patents

Abstract

PURPOSE:To prevent noise from mixing with a reproduced signal due to discharge of built-up electric charge by exposing one part of a thin metal magnetic film on a side surface of its magnetic head core and electrically connecting it with a metal base body for supporting the magnetic head core. CONSTITUTION:One part 1b of the thin metal magnetic film 1 of a magnetic head 10 is exposed on a magnetic head fitting surface 2b, and the fitting surface 2b is brought into contact with the head supporting base body 5 made of metal. That is, the thin metal magnetic film 1 exposed on the fitting surface 2b of the magnetic head 10 is electrically connected with the magnetic head supporting body 5 made of metal. Consequently, electric charge generated on a contact part between the magnetic head 10 and a tape is discharged via the magnetic head supporting body 5 to a ground of a device, etc., and by this action, the occurrence of noise due to an electric discharge phenomenon between the mag netic head and the tape is suppressed, and an adverse effect upon a reproduced output is eliminated. By this method, electric charge can not be built up on the metal magnetic film part 1, and a reproduced output in good quality can thus be obtained.

Description

[Detailed Description of the Invention] (a) Industrial application field Magnetic recording and reproducing devices, particularly recording electrical signals on high coercive force magnetic media such as 5-VH8 to TR18 mm video, DAT, etc. The present invention relates to a magnetic head for reproducing signals from a medium.

(b) Conventional technology In recent years, a magnetic head with the structure shown in Figure 6 has been put into practical use as a magnetic head for high-density magnetic recording and reproducing devices such as 5-iH 5.8 mm video or DAT. Yes, it is used.

In the same figure, (1) is a metal magnetic thin film created using vacuum thin film forming technology such as sputtering, vacuum evaporation, or ion blasting. An attempt has been made to reduce eddy current loss by stacking a plurality of layers with a non-magnetic oxide film interposed as an insulating layer. (2) is a substrate for supporting this metal magnetic film (1), and is made of a non-magnetic material such as crystallized glass or ceramic. (3) is the magnetic gap, (
4) is a winding hole for winding a wire for generating a magnetomotive force in this magnetic head or for converting a magnetic signal from a recording medium into an electric signal and reading it.

This kind of magnetic head is disclosed in Japanese Unexamined Patent Publication No. 64-37705 (
611B 5/127), the so-called MIG (Met- at in
Compared to Gap) Ill molded composite hemlock, it does not use ferrite for the head core material, so there is no sliding noise, and it has the characteristics of a head with high S and low inductance.

(c) Problems to be Solved by the Invention However, in a magnetic head as shown in FIG. It is not electrically connected to the base (5).

Therefore, the magnetic head is actually mounted on the cylinder and the VT
When mounted and used in R, etc., electric charge is accumulated in the metal magnetic film part (1) due to the usage environmental conditions or the type of tape used, and when the electric charge exceeds a certain amount, the gap between the metal magnetic film part (1) and the tape is removed. A discharge occurs, and this voltage change causes white noise to appear on the monitor screen in the case of a TR, and noise in the reproduced sound in the case of a DAT.

Therefore, as shown in FIG. 6, for example, the metal magnetic film part (1) of the magnetic head core and the magnetic head support base (5)
A method is adopted in which a conductive paint (6) is applied between the two and electrically connected between the two to release the accumulated charge.

However, this method increases the number of man-hours in the kneaded manufacturing process, and its reliability varies in terms of conductivity. In other words, the area where the conductive paint is applied is very small, and in addition, as part of the manufacturing process of the magnetic head, before applying the conductive paint, the magnetic head (core chip) (winter) and the support base for the magnetic head must be coated. There is a step of bonding (5) with an instant adhesive (7), at which time the adhesive (7) is attached to the metal magnetic film part (1).
) and later apply a conductive paint (6), the adhesive (7) will prevent the magnetic head (core chip) (8) from electrically connecting the magnetic head support base (5). Sometimes it won't connect. In addition, this conductive paint (6
) to the metal magnetic film part (1) and the magnetic throat support base (
5) is complicated and troublesome.

In view of the above-mentioned interlacing points, the present invention is directed to this magnetic field.
By partially changing the structure of the metal magnetic film part (1)
The purpose of this is to prevent charge from accumulating on the disc and obtain high-quality playback output.

(d) Means for solving the problem In a magnetic head having a structure in which a metal magnetic thin film is sandwiched between non-magnetic substrates, a part of the metal magnetic thin film (1) of the magnetic head (
]b) is exposed on the surface (2b) for mounting the magnetic head, and the mounting electrically releases the charge from that part by bringing the surface (2b) into contact with the metal head/nod support base (5). Create a magnetic head structure.

(E) Function When the magnetic head of the present invention is used in a magnetic recording device using a high coercive force recording medium such as a VTR, D, or 'tT, the magnetic head is attached so that the metal magnetic thin film exposed on the surface is It is electrically connected to the magnetic throat support, and discharges the electric charge generated at the contact area between the magnetic head and the tape to the ground (not shown) of the equipment etc. through the magnetic head support, and due to this action, the magnetic The generation of noise due to the radiated tq phenomenon between the head and the tape is suppressed, and the playback output is not adversely affected.

(f) Example Hereinafter, a specific example of the magnetic head of the present invention will be described in detail.

FIG. 1 is an external perspective view of the magnetic head of the present invention, and FIG.
) to (h):: External perspective view showing the manufacturing process of the magnetic head of the present invention. FIG. 3 is an external perspective view of the single magnetic head of the present invention.

In the figures, parts that are the same as those of the conventional example are given the same reference numerals and their explanations will be omitted. Figure 1 shows a magnetic head (10) of the present invention.
This figure shows the state in which the magnetic head is fixed to the metal magnetic head support base (5).The difference from the conventional magnetic head (dan) is that
The metal magnetic thin film (1) is attached to the side surface (2a) of the magnetic head (10).
), the attachment of the magnetic helad (10) is at a point exposed on the surface (2b) (see FIG. 3). Therefore, the time required for fixing the magnetic head (10) of the present invention to the magnetic head support base (5) is the exposed metal magnetic thin film (
The portion 1b) is electrically connected to the magnetic head support base (5).

Next, a method for manufacturing the magnetic head of the present invention will be described. As shown in FIG. 2(a), first, the upper and lower surfaces (lla) and (llb) of a non-magnetic substrate (11) made of crystallized plastic, ceramic or the like are adjusted to the desired parallelism, flatness, and surface. After finishing the roughness, the conductive grooves (12), which are the key point of the present invention, are processed using a grinding wheel.

Note that the direction in which the conductive grooves (12) are processed is a direction substantially perpendicular to the direction in which the bonded wafer is cut out from the bonded ingot, which will be described later. The cross-sectional shape of this groove (12) also depends on the continuity of the magnetic film (1) and the magnetic film (1), which will be described later.
1) and the magnetic head support base (5), it is preferable to have a trapezoidal shape or a triangular shape.

Furthermore, the groove depth (ho) of this conduction groove (12) will be determined later by slicing processing (Fig. 2 (h)), which will also be described later.
As shown in Figure 3, when performing
hl), that is, h o > h +.

Considering the above, the trapezoidal or triangular slope angle a (see FIG. 2(a)) of the cross section of the conduction groove (12) is preferably 30° to 60°.

The cross-sectional shape of this groove (12) may be any other shape as long as it exhibits the effects of the present invention.

Next, as shown in FIG. 2(b), a magnetic material (not shown) such as sendust or amorphous and a non-magnetic film such as S+O+ are applied to the surface (lla) on which the conductive groove (12) has been processed. A metal magnetic thin film (1) is formed by alternately stacking the metal magnetic thin film (1) to a desired thickness using a vacuum film forming technique such as slicing, vacuum evaporation, or ion alating. The thickness (1) of the metal magnetic thin film (1) corresponds to the trunk width of the magnetic head (1,0).

In addition, when forming this metal magnetic thin film (1), conduction grooves (1) are formed.
If the cross-sectional shape of 2) is trapezoidal or triangular, the film will have good continuity at the intersection (corner) of the slope of the trapezoidal or triangular shape and the film forming surface (lla), and the magnetic head (
(paddy) is less likely to cause conduction defects and its quality is stable.

Next, a glass thin film (13) for lamination bonding is applied to the surface (llb) opposite to the film-forming surface (lla) of the thin film (1) to a thickness of 1 to 5 mm using sputtering or screen printing technology. It adheres to a certain extent.

Next, as shown in Figure 2 (C), several dozen substrates (14) that have been processed as shown in Figure 2 (B) are stacked one on top of the other, and press pressure is applied in the vertical direction as indicated by F in the figure. Heat treatment is performed in a vacuum or in an inert gas such as nitrogen gas or argon gas to bond the laminated substrate (14) with the glass film (13) to create a bonded inte node (long).

Next, this bonded ingot (long) is cut along the broken line in FIG.
6). In this case, if the magnetic head (10) that is the final finished product has an azimuth angle θ, the cutting angle β
By setting 90'±θ, the metal magnetic thin film (1) of the magnetic head (O) is attached to the surface (
llb), which is advantageous in terms of magnetic properties.

FIG. 2(e) shows the bonded wafer halves (16) cut out from the bonded ingot (long) as a set of two, and the outer shape of the bonded wafers (16) has been finished to the desired dimensional accuracy using a grinding wheel or the like. 16) is shown.

Next, as shown in FIG. 2(f), the following processing is performed to make the surfaces (16a) and (16a') that were facing each other before cutting out into gear knob abutting surfaces. That is, one half of the wafer (16) is covered with the laminated magnetic thin film (1).
Glass penetration grooves (17) for glass welding the two half sets of bonded wafers are formed by grinding parallel to the wafers. The other half of the wafer (16') has a winding groove (18').
) and a chamfered cutout (19
) is applied using a grinding wheel. The direction of the second winding groove (18) and the chamfered notch (19) is the direction of the exposed metal magnetic thin film portion (l) of the metal magnetic thin film portion (1) for electrical conduction of the present invention.
b) (See Figure 3) must be processed in consideration of the fact that it will be on the side of the magnetic head support base (5) in the process of assembling the magnetic head (rice grain).

After that, the wafer bonding surface (16a), (16a'
) to the desired flatness and surface roughness. Next, one or both of the bonding surfaces (16a) and (16a') is coated with non-magnetic material so that the total film thickness is equal to the desired gap length of the magnetic head (river). Membranes, e.g.
A S+0+ film or the like (not shown) is deposited using a thin film formation technique such as sputtering.

Next, as shown in Fig. 2(g), sea urchin/・-1 plane (1
6a) and (16a゛) and insert the winding groove (18
) and the notch for placing the glass rod (]9).
0) and heat-treated in an inert gas such as nitrogen gas or argon gas while holding it with the force indicated by F in the figure to form a magnetic gap (3) at the same time as glass welding. do.

Thereafter, the upper and lower unnecessary portions of the joining block (21) are removed by grinding and polishing along the broken lines. Furthermore, the tape-contacting surface of the joint block (21) is rounded by grinding, and at the same time, the gear depth d is set to a desired value.

Next, as shown in FIG. 2(h), the joining block (
The processed block (21') in step 21) is further cut along broken lines at a certain pitch by grinding or using a device such as a wire saw to cut out individual core chiners, that is, magnetic heads (10). .

FIG. 3 shows a perspective view of the external appearance of the cut out magnetic head core tinop (ear). The same figure shows Magnetism Donyachinobu (10)
The mounting surface (2b) on the side where the is attached to the head support base (5)
) is viewed from the direction of The exposed metal thin film part (1b) of the metal magnetic thin film part (1) is connected to the metal magnetism, and the upper support base (5
) connected to t′L, the load is discharged through this part. Note that the width j of the exposed metal magnetic thin film portion (1b) is
Since the cross-sectional shape of the conduction groove (12) is trapezoidal or triangular, it is wider than the thickness of the metal magnetic thin film portion (1) formed into a film, and the thickness of the metal magnetic head support substrate (
5) be securely electrically connected to the

Further, the tape contact surface of the magnetic head has a convex cross-sectional shape as shown in the figure in order to improve contact with the tape and reduce spacing loss. This process is performed at the stage shown in FIG. 2(h), and after the R is processed, it is processed using a grinding wheel.

Thereafter, as shown in FIG. 1, this magnetic node core chimp (1,0) is attached to the magnetic head support base (5),
Complete the magnetic field by winding (not shown).

Next, an example of a pond will be described. Figure 4 shows an outline of the potting method.

As shown in FIG. 4(a), first, similarly to FIG. 2(2), a non-magnetic substrate made of crystallized glass, or ceramic, etc.
After finishing the upper and lower surfaces (11a) and (11b) of 11) to desired parallelism, flatness, and surface roughness, the conductive grooves (12') of the present invention are provided by grinding at predetermined locations.

In the embodiment shown in FIG. 4, the direction in which the conductive groove (12°) is processed is substantially parallel to the direction in which the bonded ingot is cut out after the substrates are bonded.

Therefore, in the cross-sectional shape of this groove (12″), the inclined surface (1
A part (lc') of the conductive metal thin film (1') attached on the tape 2a') is exposed on the tape contact surface (see Figure 5).
. Therefore, this metal thin film part (lc') and the nonmagnetic substrate (2
In order to prevent the boundary between the tape contact surface (2c') and the tape contacting surface (2c') from acting as a pseudo-magnetic gigang (3'), the cross-sectional shape of this groove (2') is shown in Figure 4 (a). It is preferable to have a triangular or trapezoidal shape such that the boundary portion is non-parallel to the original magnetic gap (3). Also, the second
Similar to the embodiment shown in the figure, in order to increase the continuity of the metal magnetic thin film (1゛) and the contact area between the exposed metal thin film portion IIthl (ld') and the magnetic head support base (5), the triangular shape is used.
Alternatively, a trapezoidal shape is preferable.

Furthermore, as in the case of Fig. 2, the depth of the second conductive groove (12') must be such that it reaches the side surface when the slining process is performed later, as shown in Fig. 5. Must be.

Thermally, the cross-sectional shape of this groove (]2') may be a shape other than J'J as long as it exhibits the effects of the present invention.

Next, as shown in Figure 4(b), a magnetic material is deposited on the side of the surface (lla) on which the conductive groove (12°) has been processed, by vacuum deposition, such as spacing, vacuum evaporation, or ion blating. The metal magnetic thin film is deposited to the desired thickness using technology.
) to form.

Next, a glass thin film (13) for lamination and bonding is formed on the opposite surface (llb>) by sputtering, screen printing, or the like.

Next, a substrate (14
') in a vacuum with press pressure applied.
Alternatively, the substrate (14'
) glass l1l (13) is melted and bonded to create a bonded ingot (15') (see FIG. 3(c)).

Next, this bonded ingot (15') is cut into half bonded wafers (16°) by grinding or free abrasive processing along the broken line in FIG.

After that, as in Fig. 2, the bonded Ueno\-half body (16°
) are made into a set of two, and after finishing the external shape to the desired dimensional accuracy using a grinding wheel, etc., one side of the bonded wafer half (16°) is placed so that the surfaces that were facing each other before cutting will be the magnetic gear butting surfaces. A glass permeation groove (not shown) is formed by grinding in parallel with the laminated magnetic film, and a groove for winding and a chamfer for placing the glass plate are formed on the surface of the other bonded wafer half (16'). Processing (not shown) is performed using a grinding wheel.

After that, the abutting surfaces of the first magnetic gap are finished to the desired flatness and surface roughness, and a non-magnetic film (for example, 5i
0+ film) is deposited using a thin film formation technique such as sputtering.

Next, glass welding is performed and at the same time a magnetic gear knob is formed.

Thereafter, unnecessary portions are removed by grinding, grinding, etc., and the tape contact surface of the magnetic head block is rounded and at the same time the magnetic gap depth is set to a desired value.

FIG. 4(d) shows the state of the welded bronc (22) after the above processing has been completed.

Next, each magnetic head core chip (10') is cut out by grinding or cutting along broken lines at partial pitches using a device such as a wire saw.

FIG. 5 shows an external perspective view of the magnetic head core chip (river'). The magnetic hent core chip (wear) is viewed from the direction of the surface on which it is attached to the magnetic head support base (5). The exposed metal magnetic thin film portion (ld') is connected to the magnetic head support base (5) side, and charges are discharged through this portion.

The width of the exposed metal magnetic thin film portion (ld') is wider than the film thickness because the conductive groove (12') has a triangular or trapezoidal cross-sectional shape. It is electrically connected reliably to the metallic magnetic head support base (5).

After that, as in the previous embodiment, as shown in FIG.
The Fk-type hentoko chips (rice grains) are attached to the magnetic head support base (5), and winding is performed to complete the magnetic head.

(G) Effects of the Invention The present invention provides a magnetic head having a structure in which a metal magnetic thin film is sandwiched between non-magnetic substrates, in which a part of the metal magnetic thin film is exposed on the side surface of the magnetic head core, and a metal Since the magnetic head is electrically connected to the base made of aluminum, it is possible to prevent noise from being mixed into the reproduced signal due to the discharge of accumulated charge, which occurs in conventional magnetic heads due to usage environmental conditions or the type of tape used. , has an effective removal effect.

Additionally, in order to prevent this discharge noise, the extra man-hours of applying conductive paint between the metal magnetic film and the head support substrate are no longer required, and the quality and performance of the magnetic head is improved. .

[Brief explanation of the drawing]

Fig. 1: An external perspective view showing a specific embodiment of the magnetic head of the present invention, Fig. 2 (a) to (h): Diagrams for explaining another magnetic head manufacturing process, Fig. 3 2 is a perspective view of the external appearance of a magnetic head core chip manufactured by the manufacturing method shown in FIG. 2, FIGS. The figure shows the manufacturing method shown in Figure 4.
A perspective view of the external appearance of the magnetic head core chip manufactured by
FIG. 6 is an external perspective view showing a conventional example. (1)...Metal magnetic thin film, (lb), (ld)...
・Exposed metal magnetic thin film portion, (2), (11)...Nonmagnetic substrate, (5)...Magnetic head support base, (10)...
・Magnetic-・Nod (core chip) e

Claims (2)

[Claims] (1) A magnetic head having a structure in which a metal magnetic thin film is sandwiched between nonmagnetic substrates, wherein a part of the metal magnetic thin film is exposed on a mounting surface of the magnetic head. (2) The magnetic head according to claim 1, wherein the metal magnetic thin film exposed on the mounting surface of the magnetic head is electrically connected to a metal magnetic head support base.