JPS6350911A - Production of composite type magnetic head - Google Patents

Abstract

PURPOSE:To obtain a composite type magnetic head having a good crosstalk characteristic by joining core half body blocks integrally via a nonmagnetic material to a magnetic gap forming surface to constitute a core block, and cutting the same in and at the prescribed position and angle to constitute a magnetic core body. CONSTITUTION:The nonmagnetic plate 51 is joined to a substrate 50 consisting of a magnetic ferrite material and grooves 33 having slopes 53a are so formed to the nonmagnetic plate 51 as to communicate with the substrate 50. A magnetic metallic film having the saturation magnetic flux density higher than the saturation magnetic flux density of the ferrite material is deposited and formed on the slopes 53a at the film thickness approximately equal to the track width; thereafter, the nonmagnetic material 57 is packed in the grooves 52 to provide a pair of the core half body blocks 59 formed in such a manner that one end face 58 of the substrate 50 acts as the magnetic gap forming surface. The magnetic film 55 of the one core half body block 61 is partly notched to form a winding groove 60. The blocks 59 and 61 are integrally joined via the nonmagnetic material to the end face 58 in such a manner that the magnetic film 55 forms the track width to constitute the core block 64. The core block 64 is cut along cutting lines 65 parallel with the slopes 53a, by which the magnetic core body 66 is obtd.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a magnetic head used in a magnetic recording/reproducing device, and in particular a combination of a magnetic ferrite with excellent high frequency characteristics and a magnetic metal film with a high saturation magnetic flux density. The present invention relates to a method of manufacturing a composite magnetic head.

(Prior Art and its Problems) Similar to video tape recorders, high-density recording is progressing in magnetic recording and reproduction of information recording and reproduction devices such as HDDs (hard disk drives).

High-density recording can be achieved by narrowing the recording track width and shortening the recording wavelength, but a recording medium with high coercive force is suitable for short wavelength recording, and corresponding to this recording medium, A magnetic head is required that has a magnetic core with high saturation magnetic flux density and excellent frequency characteristics, and also has a narrow magnetic gap capable of reproducing short wavelength recording signals.

For such a magnetic head, for example, as shown in FIG. 10, a metal magnetic film or a metal magnetic plate 10 made of Sendust (registered trademark), amorphous, etc. with a high saturation magnetic flux density is used, and a non-magnetic material is used to improve frequency characteristics. Insulating film 11 made of
A metal core 12 having a predetermined track width W is formed by laminating several layers through the metal core 12, and a pair of magnetic core halves 14 and 15 are provided in which the metal core 12 is sandwiched and reinforced by non-magnetic plates 13. , at least one magnetic core half 1
A winding groove 16 is formed in each of these magnetic core halves 14.
A magnetic head has been proposed that includes a magnetic core body 18 in which two magnetic core bodies 15 are integrally joined via a magnetic gap material 17.

In this magnetic head, the magnetic path is composed only of the metal core 12, so when the track width W becomes narrower, the cross-sectional area of the magnetic path also becomes narrower, increasing magnetic resistance, and as a result, recording and reproducing efficiency decreases significantly. There was a problem that it was not desirable. Furthermore, when the track width W becomes wider, it is necessary to laminate a number of metal magnetic plates in order to prevent eddy current loss and improve frequency characteristics, which is disadvantageous in terms of cost.

In order to solve the above problems, as another conventional example, as shown in FIG. It has a magnetic core body 22 in which a metal core part 21 is formed by depositing a metal magnetic film such as sendust or amorphous on a ferrite core 19 with a high saturation magnetic flux density near the magnetic gap 20.
A so-called composite magnetic head has been proposed.

However, in this magnetic core body 22, the metal core 2
1 to configure the track width W, the ferrite core 1
Two inclined surfaces 19a on the magnetic gap 2o forming surface side of 9,
19b is formed, and this protrusion 19c is formed.
An inclined surface 19a including 9c.

As a result of the configuration in which the metal core 21 is formed on the slanted surface 19a, 19a, and 191) when used,
, the metal core 21°21 provided in the V-shaped groove 2
This V-shaped groove 23 acts as a pseudo-gap with respect to the magnetic gap 20, picking up recording signals from adjacent tracks and deteriorating crosstalk characteristics.

In particular, as shown in FIG. 12, in the floating magnetic head 24 used in the )-IDD, the magnetic core body 22 is embedded in a base 26 having a wide slider surface 25, and the recording medium slide of the magnetic core body 22 is The moving surface 22a is configured to be flush with the slider surface 25, and when in use, the slider surface 25 is configured to float above the hard disk, which is the recording medium. Compared to the case where the tracks are in sliding contact with each other, the problem is more likely to deteriorate, and the crosstalk output from adjacent tracks is -30 to -35 dB in recording/playback characteristics.
There was a drawback that the degree of

Further, in the floating magnetic head 24, as described above, the magnetic core body 22 is embedded in the notch 27 provided in the base 26, and the recording medium sliding surface 22 is flush with the slider surface 25. Polishing is performed, and at that time, the gap depth, which is the life dimension, is measured using the magnetic core body 22.
Since it is embedded in the base, it has the disadvantage that it cannot be operated from the side like a normal magnetic head.

(Means for Solving the Problems) The present invention has been made to solve the above problems, and includes bonding a non-magnetic plate to one plane of a substrate made of magnetic ferrite material, and attaching at least A groove having an inclined surface with respect to one plane of the substrate is formed so as to communicate with the substrate, and a metal magnetic film having a saturation magnetic flux density higher than that of the magnetic ferrite material is formed on the inclined surface in a predetermined track. A core half block is formed by depositing a film to a thickness substantially equal to the width, filling the groove with a nonmagnetic material, and forming one end surface side of the substrate having the side surface of the groove to serve as a magnetic gap forming surface. A pair of core half blocks are provided, a winding groove is formed by cutting out a part of the metal magnetic film on the magnetic gap forming surface side of at least one of the core half blocks, and the metal film is connected to a predetermined track of the pair of core half blocks. A core block is constructed by integrally joining the magnetic gap forming surface via a non-magnetic material so as to form a width, and a main body of the magnetic core is constructed by cutting this block at a predetermined position and angle. An object of the present invention is to provide a method for manufacturing a composite magnetic head characterized by the following.

(Example) FIG. 1 is a perspective view of a magnetic core main body 30 of a composite magnetic head according to the present invention, and the following description will be made with reference to the same figure. 31
．． 32 is a pair of magnetic core halves, with abutting surfaces 31a,
32a through a thin film made of a non-magnetic material such as Sio2, and forms a magnetic gap 34 on a recording medium sliding surface (hereinafter referred to as sliding surface) 33.

Each of the magnetic core halves 31 and 32 includes a ferrite core 35 made of a magnetic ferrite material, and a ferrite core 3 made of a magnetic ferrite material.
For example, ceramic, integrally joined to the front part of 5.
A non-magnetic block 36 made of crystallized glass or the like having excellent wear resistance and strength, and a sliding surface 36a formed by the non-magnetic block 36 having a desired recording track width approximately in the longitudinal center thereof, and In the V-shaped groove 37 formed by the groove 37a communicating with the ferrite core 35 and the groove 378 continuous with the groove 37a and penetrating toward the side portion 36b of the non-magnetic block 36, for example, It is composed of a metal core 38 provided by filling a metal magnetic film made of sendust, amorphous, or the like. These metal parts 38 and 38 provided on the magnetic core halves 31 and 32 are abutted on the sliding surface 33 to form a magnetic head 34.

Winding windows 39 are formed on the abutting surface 31a of one of the magnetic core halves 32, and a coil (not shown) is wound using these three winding windows.

40 is a bonding glass having a low melting point, which is filled in a part of the winding window 39 to bond the magnetic core halves 31 and 32 together. The portion is exposed as a triangular shape 40a. As described above, according to the composite magnetic head of the present invention, only the metal core 38 sandwiched between the non-magnetic material blocks 36 forms the magnetic gap 34 on the sliding surface 33 in contact with the recording medium. Because it is exposed, a pseudo gap that picks up signals from adjacent tracks is not formed, making it possible to create a composite magnetic head with excellent crosstalk characteristics.

In addition, the vicinity of the magnetic gap 34 is composed of a metal core 38 made of a metal magnetic film having a high saturation magnetic flux density, and the other main magnetic path is composed of a magnetic ferrite 35 with excellent high frequency characteristics, so it has a high coercive force. This enables a composite magnetic head that can perform sufficient recording on a recording medium and has excellent recording and reproducing efficiency.

Next, a method for manufacturing the above magnetic core body 30 will be explained.

FIGS. 2 to 8 are schematic explanatory diagrams of main steps for explaining one embodiment of the method for manufacturing the magnetic core body 30 shown in FIG. 1.

The first step is as shown below, and as shown in FIG. 2, for example, ceramic,
A first core half block 52 is obtained by bonding rectangular nonmagnetic plates 51 made of crystallized glass or the like together using a bonding agent such as high melting point glass.

The second step is as shown below, and as shown in FIG.
V having an inclined surface 53a having an angle of 5° to 90°
A second core half block 54 is obtained by forming a plurality of grooves 53 in the shape of a letter at predetermined intervals so that the grooves 53 are deep enough to reach the ferrite substrate 50 or more. This groove 53 is necessary for providing the metal core 38 in FIG.
When the metal magnetic film 55 described later in a is provided, the ferrite substrate 50 and the metal magnetic film 55 can be magnetically coupled, and the shape of the groove 53 is not limited to the V-shape.

The third step is as shown below, and as shown in FIG. For example, Fe-8 with high saturation magnetic flux density
A second core half block 56 is obtained by forming a metal magnetic film 55 made of i-based, Fe-AI-8i-based, CO-based, etc. by vacuum thin film forming means such as vacuum evaporation, sputtering, and ion blasting.

Through this step, the metal magnetic film 55 and the substrate 50 are magnetically coupled. Metal magnetism at this time W! The thickness of 55 is equivalent to the track width.

Further, as a protective film on this metal magnetic film 55, for example,
Si02, AJ! , 203, Ding 102. If a thin film (not shown) such as CR is deposited, it will have the effect of preventing chemical reactions such as oxidation and diffusion of the metal magnetic film 55 when filling the groove 53 with a non-magnetic material as explained in the next step. There is.

The fourth step is as shown below, and as shown in FIG. The core half block 57 is filled and finished by polishing so that the end face on which the groove 53 is formed becomes the abutting face 58, thereby obtaining the core half block 59 shown in FIG.

Instead of providing the non-magnetic material 57 by heat welding low melting point glass, it may also be provided by molding crystallized glass or ceramic so that it can fit into the groove 53 and joining it through low melting point glass or the like. Generally, according to the latter method, a non-magnetic material with excellent wear resistance is exposed on the sliding surface of the magnetic head, resulting in a magnetic head with excellent wear resistance.

The fifth step is as shown below, and as shown in FIG. 6, the fourth core half block 59 obtained in the fourth step is
A portion 5 of the metal core on the inclined surface 53a within the abutting surface 58 of
The winding groove 60 is formed so that the wire portion 5a remains on the abutting surface 58, thereby obtaining a fifth core half block 61.

The sixth step is as shown below, and as shown in FIG. 7, the fourth core half block 59 obtained in the fourth step and the fifth core half block 59 obtained in the fifth step are and the body block 61 are butted together with a thin film made of a non-magnetic material such as 5i02 interposed between these abutting surfaces 58° and 58, and a part of the winding groove 60 is filled with low melting point glass 62, and they are joined together. A core block 64 having a magnetic gap 63 is obtained.

The seventh step is as shown below, and as shown in FIG. 7, by sequentially cutting the core block 64 along cutting lines 65 parallel to the inclined surface 53a, a plurality of magnetic A core body 66 is obtained.

The eighth step is as shown below, and as shown in FIG. , a magnetic core 30 shown in FIG. 1 can be obtained in which a sliding surface 69 is formed by the polished cutting line 68.

Next, in the magnetic core 30 shown in FIG. 1, the distance from the tip of the triangular non-magnetic material 40a exposed on the sliding surface 36a of the magnetic core half 32 having three winding grooves to the metal core 38. By measuring S, the metal core 38 (not shown) is
The fact that the lifespan method d can be estimated will be explained using FIG.

FIG. 9 shows a magnetic gap 63 of a magnetic core half body 61 having a winding groove 60 in the magnetic core body 30 shown in FIG.
FIG. 6 is a perspective view showing a cross section near the sliding surface 69 along . The distances from the tip of the triangular non-magnetic material 62a to the film surface of the metal magnetic film 55 are respectively Sl and 82, and the winding groove 60
If the angle between the cut line 60a and the sliding surface 69 is θ2, then the life dimension di expressed by the length of the metal magnetic film 55 is
.

d2 can be expressed by the following equation.

d1=81-tanθ2...
(1) d2=s2−tanθ2−(2
) Also, the slope θ1 of the groove 53 shown in FIG. 3 and the above θ
2 has the following relationship: θ2-90-θ1 (3), so equations (1) and (2) each have d 1
=S 1-tan (90°-θ1) ・”
(4) d 2 = 8 2 - tan (90'
-θ1 ) =・(5) Since each slope θ1 can be known in advance,
By substituting the measured value of the distance 31.32 into equations (4) and (5), the life dimensions d1 and d2 can be accurately estimated.

In particular, in the HDD magnetic head 24 described above, the life dimension cannot be measured from the side surface of the magnetic head, but when the magnetic core body 30 of the present invention is used, the triangular non-magnetic material 62a exposed on the sliding surface 67 It has the advantage that the life dimension can be easily calculated by measuring the distance Sl, 32 from the tip to the film surface of the metal magnetic film 55.

Furthermore, as is clear from equations (4) and (5), if the inclination angle θ of the groove 53 is reduced, the difference between the life dimensions d1 and d2 increases, so the inclination angle θ1 of the groove 53 is set to 456 to 90°. As mentioned above, this is desirable.

(Effects of the Invention) As explained above, according to the manufacturing method of the present invention, only the metal core sandwiched between the non-magnetic material blocks is exposed on the sliding surface in contact with the recording medium. No pseudo gaps are formed to pick up signals, making it possible to manufacture magnetic heads with excellent crosstalk characteristics.

In addition, the life dimension can be determined by measuring the distance from the tip of the triangular non-magnetic material for bonding exposed on the sliding surface to the film surface of the metal core, making it easier to manage the life dimension. This makes it possible to manufacture highly reliable magnetic heads.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a magnetic core body of a composite magnetic head according to the present invention, and FIGS. 2 to 8 are diagrams for explaining an embodiment of a method for manufacturing the magnetic core body 30 shown in FIG. A schematic explanatory diagram of the main steps, FIG. 9 is a perspective view showing a cross section near the sliding surface along the magnetic gap of the magnetic core half having the winding groove in the magnetic core body shown in FIG. 8, and FIG. 10 11 is a perspective view showing a conventional magnetic head made of a metal core, FIG. , 55...
・Metal magnetic film, 57... Non-magnetic material, 58... Butt surface, 60... Winding groove, 62... Low melting point glass, 63
... Magnetic gap, 64... Core block, 65.
... Cutting line, 67°68... Polishing cutting line, 69...
Recording medium sliding surface.

Claims (1)

[Claims] A non-magnetic plate is bonded to one plane of a substrate made of magnetic ferrite material, and a groove having at least an inclined surface with respect to one plane of the substrate is formed in this non-magnetic plate so as to communicate with the substrate, and at least this inclination After a metal magnetic film having a saturation magnetic flux density higher than the magnetic ferrite material is deposited on the surface to a thickness approximately equal to a predetermined track width, the groove is filled with a non-magnetic material, and the side surfaces of the groove are A pair of core half blocks are provided with one end surface of the substrate having a magnetic gap forming surface, and a part of the metal magnetic film is cut out and wound on the magnetic gap forming surface of at least one of the core half blocks. A core block is constructed by forming a line groove and integrally joining the pair of core half blocks to the magnetic gap forming surface via a nonmagnetic material so that the metal film forms a predetermined track width. A method for manufacturing a composite magnetic head, characterized in that a magnetic core body is constructed by cutting this block at a predetermined position and angle.