JPS62124610A - Magnetic head - Google Patents

Abstract

PURPOSE:To obtain the titled head having an excellent magnetic characteristic, and to improve an output of the head by constituting it so that a specified relational expression with regard to a magnetic flux flow area of a core base body, a saturation magnetic flux density, a film of a high saturation magnetic flux density, etc. CONSTITUTION:In a magnetic gap opposed area S1, an area S2 opposed to an operation gap of a projecting part of a core base body, and a magnetic flux flow area S3 of an inclined part of a winding window, the titled head is constituted so that a relation of said each area S1, S2 and S3 a saturation magnetic flux density Bsh of a magnetic thin film 31 having a high saturation magnetic flux density, and a saturation magnetic flux density BsL of a core bass body 30 side becomes B/A=1 or above, at the time of S1XBsh=A, S2XBsL +S3XBsh=B. The magnetic head for satisfying said relational expression is excellent in its magnetic characteristic because the part shown by a sectional area S1 of a magnetic gap is scarcely brought to a magnetic saturation. In this regard, until the magnetic flux is saturated in the gap joint surface, it is not saturated in other magnetic path than the gap joint surface, therefore, an output of the head is improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic head, and particularly relates to a core base portion whose side surface facing a magnetic gap is inclined with respect to the magnetic gap surface, and the core base portion. The present invention relates to a magnetic head having a core half including a magnetic thin film made of a magnetic material having a high saturation magnetic flux density and coated on the side surface facing the magnetic gap.

[Conventional technology]

With the increase in the density of magnetic recording, the coercive force of magnetic recording media has been increased, and a magnetic head that can record on this magnetic recording medium is made of a magnetic material with a high saturation magnetic flux density, at least in the portion facing the magnetic gap. A magnetic head is being proposed.

FIGS. 9 and 10 are a partial plan view and a partial sectional view of this type of magnetic head.

This magnetic head includes a first core half 1 and a second core half 2.
and an excitation coil 3 wound around the first core half 1. The first core half 1 and the second core half 2 are made of a core base 5 made of ferrite or the like and having a chevron-shaped protrusion 4 approximately at the center of the side surface facing the magnetic gap.
and a magnetic thin film 6 having a high saturation magnetic flux density attached to the side surface of the core base 5. As shown in FIG. 9, the protrusion 4 and the magnetic thin film 6 of one example of the first core half
Furthermore, the shapes of the protrusion 4 and the magnetic thin film 6 on the second core half 2 side near the joint are substantially symmetrical with respect to the left and right sides of the magnetic gap. 8 is a reinforcing layer made of a non-magnetic material such as glass.

In such conventionally proposed magnetic heads, the magnetic flux distribution cross section of the core body (protrusion) near the magnetic gap, the saturation magnetic flux density (B3L) of the core body, the film thickness for high saturation magnetic flux density, etc. are sufficiently determined. No consideration has been given. For this reason, the protruding part of the core base 5 and the inclined part of the winding window become magnetically saturated before the part near the surface facing the magnetic gap becomes magnetically saturated, resulting in the problem that desired magnetic properties cannot be obtained. be.

[Problems to be solved by the invention] The purpose of the present invention is to solve the problems of the prior art described above,
An object of the present invention is to provide a magnetic head having excellent magnetic properties.

[Means to solve the problem]

To achieve this objective, the inventors developed a core substrate (
As a result of careful consideration of the magnetic flux distribution area of the protruding part, the saturation magnetic flux density of the core base, the film with high saturation magnetic flux density, etc., we joined two core halves each having a core base through a magnetic gap, and In a magnetic head that has a protrusion on the side surface facing the core half and a magnetic thin film having a high saturation magnetic flux density is coated on the protrusion, the cross-sectional area of the magnetic gap (S+) x the high saturation magnetic flux density The saturation magnetic flux density (Bsh) of the magnetic thin film having a high saturation magnetic flux density (Bsh) = A, the saturation magnetic flux density (BSL) of the protruding part of the core base, the magnetic flux circulation area of the inclined part of the child winding window (S3) x the magnetic thin film having a high saturation magnetic flux density of 4. A magnetic head configured such that B/A=1 or more has been achieved when saturation magnetic flux density (B)-B.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view of the magnetic head according to the first embodiment, and FIG.
The figure is a sectional view taken along the line E in FIG. 1.

This magnetic head is used in a magnetic disk recording/reproducing device, and includes a recording/reproducing head 21, an erasing head 22,
It is mainly composed of a non-magnetic material 23 for preventing magnetic influence between both magnetic heads. These integral parts are attached to a head holder (not shown) so that the erasing head 22 is disposed on the upstream side in the running direction of the magnetic recording medium (magnetic disk).

The recording/reproducing head 21 mainly includes a first core half 24 , a second core half 25 facing the first core half 24 , and an excitation coil 27 wound around a coil groove 26 provided in the first core half 24 . has been done. 28 is a reinforcing layer made of a non-magnetic material such as glass lath, and is provided near the joint between the first core half 24 and the second core half 25.

The first core half 24 has a first core base 3 having a chevron-shaped protrusion 29 approximately at the center of the side surface facing the magnetic gap 35.
0 and a first magnetic thin film 31 adhered to the side surface.

For the first core base 30, a ferrite having high magnetic permeability, such as manganese-zinc ferrite or nickel-zinc ferrite, is used.

On the other hand, for the first magnetic thin film 31, a crystalline alloy or an amorphous alloy having high saturation magnetic flux density and high magnetic permeability is used. Examples of such crystalline alloys include iron-aluminum-silicon alloys, iron-silicon alloys, and iron-nickel alloys. In addition, amorphous alloys include iron, nickel,
one or more elements selected from the group of cobalt;
An alloy consisting of one or more elements selected from the group of phosphorus, carbon, boron, and silicon, or an alloy containing this as a main component, such as aluminum, germanium, beryllium, tin, molybdenum, indium, tungsten, titanium, manganese, There are alloys to which elements such as chromium, zirconium, hafnium, and niobium are added, and alloys containing cobalt and zirconium as main components and the above-mentioned additional elements.

The 2-17th A half body 25 is similar to the 1st:1 A half body 24,
A second core base 33 made of ferrite with high magnetic permeability and having a chevron-shaped protrusion 32 at approximately the center of the side surface facing the magnetic gap 35, and a high saturation magnetic flux density and high magnetic permeability coated on the side surface thereof. and a second magnetic thin film 34 made of a metallic magnetic material. As shown in Figure 1, the first
The protrusion 29 on the core half 24 side and the first magnetic thin film 31
The protruding portion 32 and the second magnetic thin film 34 on the second core half 25 side have substantially symmetrical shapes in the vicinity of the joint portion with the magnetic gap 35 interposed therebetween. This magnetic gap 3
5 has a length of about 50 to 200 μm.

On the other hand, the erasing head 22 mainly consists of a first core half 36 , a second core half 37 facing the first core half 36 , and an excitation coil 39 wound around a coil groove 38 provided in the second core half 37 . It is configured. A reinforcing layer 40 is made of a non-magnetic material such as glass, and is provided near the joint between the first core half 36 and the second core half 37.

The first core half 36 includes a first core base 43 made of ferrite with high magnetic permeability and having two chevron-shaped protrusions 42 at a predetermined interval on the side facing the magnetic gap 41; It is composed of a first magnetic thin film 44 made of a metallic magnetic material having a high saturation magnetic flux density and high magnetic permeability.

Similarly to the first core half 36, the second core half 37 is a second core made of high magnetic permeability ferrite and has two chevron-shaped protrusions 42 at a predetermined interval on the side facing the magnetic gap 41. It is composed of a base body 46 and a second magnetic thin film 47 made of a metallic magnetic material having high saturation magnetic flux density and high magnetic permeability and adhered to the side surfaces of the base body 46. Therefore, as shown in FIG. 1, the protrusions 42 and the first magnetic thin film 44 of the 36 first core halves, and the protrusions 45 of the second core half 37
In addition, the shape of the second magnetic thin film 47 in the vicinity of the joint portion is substantially symmetrical with respect to the magnetic gap 36 .

Magnetic gap 35 of recording/reproducing head 21 and erasing head 2
The two magnetic gaps 42 shown in FIG. 2 have a positional relationship as shown in FIG. is partially erased and the track width is regulated.

FIG. 3 is an explanatory diagram showing the relationship between each member in the present invention. In Figure 3, the area facing the magnetic gap (S), the area facing the working gap of the protruding portion of the core base (SZ), and the magnetic flux circulation area of the inclined portion of the winding window (B3) are the areas shown in the figure, respectively. It shows. The relationship between these areas S1, SZ, and B3, the saturation magnetic flux density (Bh) of the magnetic thin film 31 having a high saturation magnetic flux density, and the saturation magnetic flux density (Bit) on the core base 30 side is s
+x13=A SZ XBsL+S3 When XBsh=B, the configuration is such that B/A=1 or more.

That is, the above A (S + ×B sh) corresponds to the allowable amount of magnetic flux flowing through the cross-sectional area of the magnetic gap, and Sz
×Bit (B+) corresponds to the allowable amount of magnetic flux flowing through the area portion of the protruding portion of the core base body facing the working gap, and B3 XBsh (Bz) corresponds to the allowable amount of magnetic flux in the inclined portion of the winding window.

This relationship between each member is important in terms of magnetic properties,
If the allowable magnetic flux amount represented by the allowable magnetic flux quantum B2 represented by B1 is smaller than the allowable magnetic flux amount represented by A, the portion represented by the cross-sectional area S1 of the magnetic gap becomes magnetically saturated earlier,
Recording and playback becomes impossible. On the other hand, in a magnetic head that satisfies the relational expression in the present invention, the portion indicated by the cross-sectional area S1 of the magnetic gap is less likely to be magnetically saturated, and therefore has poor magnetic properties.

In the present invention, as a suitable example for increasing the length of the magnetic gap 35, in other words, the recording track width, in FIG. Two or more magnetic thin films 32 are arranged in parallel, and a first magnetic thin film 31 and a second magnetic thin film 34 are deposited thereon.

The first core half body 24 and the second core half body 25 shown in FIG. 4 are formed by vapor deposition, sputtering, After forming the magnetic thin film 31 (34) by, for example, cutting off the chevron-shaped portion corresponding to the protrusion of the protrusion 29 (32) formed at the tip of the magnetic thin film 31 (34), as shown by the two-dot chain line. Created by

FIGS. 6 and 7 are plan views showing main parts of a third embodiment and a fourth embodiment of the present invention, respectively. In the third embodiment shown in FIG. 6, a core base 59 constituting a core half 58 has an inclined surface 60, and a protrusion 61 consisting of two protrusions is formed in a portion facing the magnetic gap. There is,
Moreover, the tip 62 of the protrusion of the protrusion 61 has a linear shape with a length that does not form a magnetic gap.

Further, in the fourth embodiment shown in FIG. 7, the core half 63
A core base 64 constituting the core body 64 has an inclined surface 65, and a protrusion 66 consisting of two protrusions is formed in the portion facing the magnetic gap, and the tip 67 of the protrusion of the protrusion 66 has a curved shape. It has become. In addition, 68.69 in FIGS. 6 and 7 is the same magnetic thin film 68.69.
70.71 indicated by a two-dot chain line indicates an ablation line of the magnetic thin film 68, 69, that is, a portion where a magnetic gap is formed.

In the third and fourth embodiments configured in this way, the track width can be set large, the thickness of the magnetic thin film can be suppressed, and the protrusion portions 61.66 constituting the core base 59.64 can protrude. Since the tip has a straight or curved shape, it has sufficient strength against external forces and is easy to handle.

Also in the second to fourth embodiments described above, magnetic heads with excellent magnetic properties can be obtained by configuring them so as to satisfy the relational expressions described in the first embodiment.

Next, as shown in FIG. 4, two chevron-shaped protrusions are provided on the core substrate, and the Co-Nb-
Zr (high saturation magnetic flux density material) was deposited. This high saturation magnetic flux density material has Bs=9500 Gauss, which is larger than the Bs of the ferrite constituting the core base, which is approximately 5000 Gauss.

Magnetic heads were manufactured by varying the thickness of the high saturation magnetic flux density material adhered to the core substrate.

α-metallic iron powder is used as the magnetic powder for high-density recording media, and H
The measurement was carried out using a medium of c=15500e, Br"1500 Gauss. The measurement results are shown in FIG.

FIG. 8 shows the relationship between the above-mentioned B/A value and the head output of the magnetic head. As is clear from Figure 8, B/
When A is 1 or more, the head output is 0 or more, indicating that the magnetic properties are excellent.

〔Effect of the invention〕

As described above, according to the present invention, the magnetic flux is not saturated in the magnetic path other than the gear lub joint surface until it is saturated at the gear lub joint surface, so the head output is improved and the coercive force of the metal medium is 15.
It is possible to sufficiently record on a medium of about 000e.

[Brief explanation of drawings]

FIG. 1 is a plan view of a magnetic head according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the E-I line in FIG. 1, and FIG. 3 is an explanation for showing the relationship between each member in the present invention. Figure, 4th
The figure is a plan view of essential parts of a magnetic head according to the second embodiment of the present invention, and FIG. 5 is an explanatory diagram showing an example of manufacturing the magnetic head shown in FIG.
FIG. 6 is an explanatory diagram showing an example of manufacturing a magnetic head according to a third embodiment of the present invention, FIG. 7 is an explanatory diagram showing an example of manufacturing a magnetic head according to a fourth embodiment of the invention, and FIG. A graph showing the relationship between the relational expression B/A and the head output in the present invention,
FIG. 9 is a partial cross-sectional view of the magnetic head, and FIG. 10 is a partial cross-sectional view of FIG. 21...recording/reproducing head, 22...erasing head, 24.36...first core half, 25.37...
...Second core half, 29.32.42.45...
... protrusion, 30.43 ... first core base,
31.44...First magnetic thin film, 33.46...
...Second core base, 34.47...Second magnetic thin film, 35.41...Magnetic gap, S,...
......Cross-sectional area of the magnetic gap, S2...Area of the protruding portion of the core base facing the operating gear-up, S3......Magnetic flux circulation area of the inclined portion of the winding window, Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Factor Figure 8 1.0 2.0%

Claims (1)

[Claims] (1) Two core halves each having a core base are joined via a magnetic gap, and at least one of these core halves has a protrusion on the side surface facing the other core half. In a magnetic head in which a magnetic thin film having a high saturation magnetic flux density is coated on the protrusion, the cross-sectional area of the magnetic gap (S_1) x the saturation magnetic flux density of the magnetic thin film having a high saturation magnetic flux density (B_s_h) = A. When saturation magnetic flux density of the protruding portion of the core base (B_S_L) + magnetic flux circulation area of the inclined portion of the winding window (S_3) x saturation magnetic flux density of the magnetic thin film having high saturation magnetic flux density (B_s_h) = B, A magnetic head characterized in that it is configured such that B/A=1 or more.