JPS61145712A - Magnetic head - Google Patents

Abstract

PURPOSE:To decrease the time needed for formation of a magnetic thin film by forming a projection part with plural projections at a part where the core base of a core half is set opposite to a magnetic gap. CONSTITUTION:The projection parts 29 and 32 containing four projections are formed at the parts where the 1st and 2nd core bases 30 and 33 of a record/ reproduction head 21 are set opposite to a magnetic gap 35. Therefore magnetic thin films 31 and 34 are formed into plural chevrons at their tip parts according to the forms of parts 29 and 32. Thus the areas near the bottom parts of those chevrons formed at the tips of both films 31 and 34 can be cut when the gap 35 is formed by cutting away both films 31 and 34. In such a way, the desired track width l of 100-140mum can be obtained easily by setting properly the sizes and numbers of projections of both parts 29 and 32 respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head, and in particular to a core base whose side surface facing a magnetic gap is inclined with respect to the magnetic gap surface, and a core base of the core base. 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 deposited 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. Development of magnetic heads is progressing.

FIG. 11t is a plan view showing the main parts of this type of conventional magnetic head. The magnetic head shown in FIG. 11 includes a first core half l and a second core half 2 that are joined to face each other. A magnetic gap 3 is provided at the junction of the two. 4 is a reinforcing layer made of a non-magnetic material such as glass. Each of the first core half 1 and @22 core half 2 described above is a first core base 5.
, a second core base 6, a hole adhered to the side surface of the core base 5.6 facing the magnetic gap 3, a first magnetic thin film 7 made of a magnetic material having a high saturation magnetic flux density, and a second magnetic thin film. 8, and the side surface of each core body 5.6 facing the magnetic gap 3 is an inclined surface 9. lO, and there is a protrusion 1 in the part facing the magnetic gap 3.
1.12.

Note that the first core half l and the second core half 2 are! As illustrated in FIG. 12, the inclined surface 9 (10
), a magnetic thin film 111j7 is formed by vapor deposition, sputtering, etc.
After forming (8), the tip portion of the magnetic thin film 7 (8) is cut off as shown by the cutting line 13 shown by a two-dot chain line l1
l (therefore produced.

[Problem that the invention seeks to solve]

By the way, there is no particular problem with magnetic heads for general cVTRs because the track width l shown in FIG. 11 is about 10 μm.
)'! Requires a trunk width j of 100-140 μm,
If this track width j is smaller than 100 μm, tracking accuracy will be adversely affected. Therefore, in the conventional magnetic head shown in FIG.
In this way, the track width of Zoo-140μm! In order to form the magnetic thin film 7(8), as shown in FIG.
The thickness t must be set sufficiently large in advance.

However, in this way, the thickness t of the magnetic thin film 7 (8) is
Since the magnetic thin film 7 (8) is formed by vapor deposition, sputtering, etc., it takes time to form the magnetic thin film 7 (8), which increases the number of man-hours for manufacturing the magnetic head. Furthermore, when the thickness t of the magnetic thin film 7(8) becomes large, eddy currents are generated in the magnetic thin film 7(8) portion during use of the magnetic head, resulting in deterioration of magnetic properties.

Note that instead of the magnetic thin film 7 (8), it is possible to provide a thin film with a laminated structure in which a non-magnetic thin film is interposed between magnetic thin films, and to reduce the thickness of one magnetic thin film. It is difficult to manufacture such a laminated structure in reality, and even if it were possible to manufacture it, it cannot be denied that the manufacturing cost would be high.

The present invention has been made in consideration of the actual situation in the prior art, and its purpose is to enable the track width of the magnetic gap to be set sufficiently thick and to suppress the thickness of the magnetic thin film. The object of the present invention is to provide a magnetic head that can perform the following functions.

[Means to solve the problem]

In order to achieve this object, the present invention focuses on the form of the portion of the core base that faces the magnetic gap, and includes a first core half and a second core half that are joined facing each other. ,
A magnetic gap is provided at the joint between the first core half and the second core half, and each of the first core half and the second core half faces the core base and the magnetic gap of the core base. A magnetic thin film made of a magnetic material having a high saturation magnetic flux density is adhered to the side surface of the first core half, and the second core half faces the magnetic gap of the core base of at least one of the first core half and the second core half. In the case where the side surface facing the magnetic gap is inclined with respect to the magnetic gap, the tip of the core body is formed so that the side surface facing the magnetic gap is inclined, and the tip is located at the portion facing the magnetic gap, for example. A protrusion consisting of a plurality of protrusions arranged in parallel, that is, a protrusion consisting of a plurality of protrusions whose tips form an acute angle, and a protrusion consisting of a plurality of protrusions whose tips form a minute linear shape along the magnetic gap. , the protrusion is provided with a protrusion consisting of a plurality of protrusions each having a curved tip.

〔Example〕

Next, the present invention will be explained with reference to the drawings regarding implementation gA.

FIG. 1 is a plan view of the composite magnetic head according to the first embodiment, and FIG. 2 is a sectional view taken along line E-II in FIG.

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

The recording/reproducing head 21 is mainly composed of a first core half 24 , a second core half 25 opposite thereto, and an excitation coil 27 wound in a coil groove 26 provided in the first half 24 . It is composed of Reference numeral 28 denotes a reinforcing layer made of a non-magnetic material such as glass, and is provided near the joint between the first half 24 and the second core half 25.

, Ill core half 24 is made up of a first core base 30 having a chevron-shaped protrusion 29 at approximately the center of the side surface facing the magnetic gap 35, and a first magnetic thin film 31 adhered to the side surface. It is configured. The protruding portion 29 described above is composed of a plurality of protrusions, for example, four protrusions, each of which has an acute angle at its tip and is arranged substantially parallel to the magnetic gap 35.

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

On the other hand, the 11a thin film 31Vct'! , crystalline or amorphous alloys with high saturation magnetic flux density and high magnetic permeability may be used. Examples of such crystalline alloys include iron-aluminum-silicon alloys, iron-silicon alloys, and iron-nickel alloys. Further, as an amorphous alloy, an alloy consisting of C1 or more elements selected from the group of iron, nickel, and cobalt and one or more elements selected from the group of phosphorus, carbon, boron, and silicon, or These are the main components of aluminum, germanium, beryllium, tin, larybdenum, indium, tungsten, titanium, manganese, chromium, zirconium, and hafnium. There are alloys to which elements such as niobium are added, and alloys containing cobalt and zirconium as main components and the above-mentioned additional elements.

Similarly to the first core half 24, the second core half 25 also has a chevron-shaped protrusion 3 approximately in the center of the side surface facing the magnetic gap 35.
a second core base 33 made of ferrite with high magnetic permeability and a second magnetic thin film 34 made of a magnetic metal material with high saturation magnetic flux density and high magnetic permeability adhered to the side surface of the second core base 33;
It is composed of. The above-mentioned protrusion 32 is also composed of, for example, four protrusions, similar to the protrusion 29 of the first core base described above, and the tip of each protrusion forms an acute angle and is arranged substantially parallel to the magnetic gap 35. has been done.

Further, as shown at t1g, the protrusion 29 on the first core half 24 side, the VC first magnetic thin film 31, and the second core half 2
The protruding portion 32 on the 5th side and the second magnetic thin film 34 have substantially symmetrical shapes in the vicinity of the joint portion with the magnetic gap 35 interposed therebetween. This magnetic gap 35 is approximately 100 to 14
It has a length of about 0 μm.

Note that the first core half 24 and the second core half 2 described above
5 is a core base 30 (33) as illustrated in FIG.
After the magnetic thin film 31 (s-4) is formed on the inclined surface and the protrusion 29 (32) by vapor deposition, sputtering, etc. It is produced by cutting out a chevron-shaped portion corresponding to the protrusion of the protrusion 29 (32).

10,000, the erasing head 22 is mainly composed of a first core half 36, a second core half 37 opposite thereto, and an excitation coil 39 wound in a coil groove 38 provided in the second core half 37. It is composed of 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 body 36 includes a first core base body 43 made of ferrite with high magnetic permeability and having two chevron-shaped protrusions 42 at a predetermined interval on the side surface 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.

Like the first core half 36, the second core half 37 is also made of high magnetic permeability ferrite and has two chevron-shaped protrusions 45 at a predetermined distance on the side facing the magnetic gap 41 f! , a 2-core base body 46, and a second magnetic thin film of 1 g made of a metallic magnetic material having high saturation magnetic flux density and high magnetic permeability, which is adhered to the side surface of the base body 46! It consists of 47. Therefore, as shown in FIG. 1, the protrusion 42 on the first core half 36 side
In addition, the first magnetic thin film 44, the protrusion 45 on the wE2 core half 37 side, and the second magnetic thin film @47 are approximately symmetrical in shape in the vicinity of the joint with the magnetic gap 41 interposed therebetween.

The magnetic gap 35 of the recording/reproducing head) '21 and the two magnetic gaps 41 of the erasing head 22 have a positional relationship as shown in Figure @1, and a recording track is formed on the magnetic recording medium by the recording/reproducing head 211C. Immediately thereafter, both ends of the recording track are partially erased by the erasing head 22 to regulate the track width.

In the first embodiment VC having this 5tc structure, the first-a base 30. of the recording/reproducing head 21. Second core base 33
Since protrusions 29 and 32 each consisting of four protrusions are provided in the portions facing the magnetic gap 35, as shown in FIG. [31 (34) has its tip formed in a plurality of chevrons following the shape of the protrusions of these protrusions 29 and 32, and therefore the magnetic thin film 31 (34)
) to form the magnetic gap 35, it is only necessary to cut out the portion near the bottom of the chevron formed at the tip of the magnetic thin film 3134).
By appropriately setting the size and number of the protrusions 2 in advance, it is possible to easily obtain the desired track width l of 100 to 140 μm.

Moreover, in this first implementation fIlrc, the magnetic gap 3
The portion of the magnetic thin film 31 (34) that is removed when forming the magnetic thin film 31 (34) is only a plurality of chevrons formed at the tip of the a-type thin film 31, and the height dimension H of the chevrons is small.
It corresponds to the height of the four protrusions composing the protrusions 29 and 32 of the k"L core base 30 (33), and therefore the height of the protrusions of these protrusions 29 and 32 is set low in advance. By doing so, the thickness of the magnetic thin film t can be minimized.

Note that the above wcl embodiment [if any, the recording/reproducing head 2
The first core base body 301@2 core base body 33 constituting the first core half body 24 and the second core half body 25 of 1 is made of high magnetic permeability ferrite, but these first core base bodies 3
0. At least one of the second core bases 33 is made of ceramic;
A non-magnetic material such as non-magnetic ferrite may be used.

FIG. 4 is a plan view showing essential parts of a second embodiment of the present invention. This second embodiment shows, for example, a recording/reproducing head, and the first core base 51 of the Kl core half 50 is made of, for example, a non-magnetic material, and has a rectangular shape without an inclined surface. be. Reference numeral 52 denotes a first magnetic thin film similar to that in the first embodiment, which is adhered to the first core substrate 51 .

Second core half body 5 provided opposite to first core cow body 50
3, the side surface of the second core base body 54 facing the magnetic gap 55 is an inclined surface, similar to the first core half body 24 and the second core half body 25 of the first embodiment described above. In a portion facing the magnetic gap 55, there is a protrusion 56 consisting of three protrusions whose tips are arranged parallel to the magnetic gap 55. 57 is a second magnetic thin film adhered to the second core substrate 51C. The second real tIl! configured in this way! 4fQ also has a track width of 100 to 140, for example.
It can be set as large as about μm, and the thickness of the magnetic thin film 52, 57 can be suppressed.

FIGS. 5 and 6 are plan views showing the main parts of the third and fourth embodiments of the present invention, respectively. In the third embodiment shown in FIG. 5, a core base 59 constituting a core half 58 has an inclined surface 6o, and a protrusion 61 consisting of two protrusions is provided at a portion facing the magnetic gap. Moreover, the tip 62 of the protrusion of this protrusion 61 has a linear shape that is substantially parallel to the magnetic gap and has a minute length, that is, a length that does not form a pseudo magnetic gap.

Further, in the fourth embodiment shown in FIG. 6, 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 misgap, and the tip 67 of the protrusion of the protrusion 66 has a curved shape. It has become. In addition, Section 5.6
In the figure, 68.69+S is the same magnetic thin film as described above, indicated by a two-dot chain line.

The third configuration configured in this way. In the fourth embodiment, the first
．． Similar to the second embodiment, the track width can be set large;
The thickness of the magnetic thin film can be suppressed, and the core substrate 59.
Since the tips of the protrusions 61 and 66 constituting 64 are linear and curved, they require sufficient strength against external forces and are easy to handle.

7 and 8 are explanatory diagrams showing a fifth embodiment of the present invention, in which FIG. 7 is a plan view showing the main part, and FIG. 8 is a detailed view of section A in FIG. 7.

In the fifth embodiment shown in FIG. 7.8, the first
': 17 half body 72) Protrusions 77 and 78 each consisting of two protrusions are provided on the portions of the first core base body 74 and the second core base body 75, which constitute the second core half body 73, facing the magnetic gap 76. Moreover, the valleys 79' and 80 of each protrusion are set so that the radius indicated by r is 15 μm or more as shown in FIG. 8, and the first core base 74. Wl, 2! A. The first magnetic thin film 8 to be deposited on the substrate 75#c, I! The magnetic thin film 82 is made of a magnetic material made of an amorphous alloy with a high saturation magnetic flux density.

In addition, when the first magnetic thin film 81 and the second magnetic thin film 82 are made of an amorphous alloy as in this fifth embodiment, the valleys 79° and 80 of the first core base 74 and the second core base 75 are radius r is 5
If it is less than μm, as illustrated in Fig. 9 (, Wc2°
The magnetic thin film 82 (same as the first magnetic thin film 81) will adhere to the valley 800 portion, increasing the magnetic resistance.
Further, when the radius "is 15 μm or more as described above, a good regeneration efficiency of 75 inches or more can be ensured as shown in FIG. 1O.

〔Effect of the invention〕

As described above, the magnetic head of the present invention has a structure in which a protrusion consisting of a plurality of protrusions is provided in the portion of the core base of the core half that faces the magnetic gap, so that the track width of the magnetic gap can be made sufficiently large. In addition, the thickness of the magnetic thin film can be suppressed, and the time required to form the magnetically dissipating thin film is shorter than in the past, reducing manufacturing man-hours and reducing manufacturing costs. It can be done cheaply.

Furthermore, since the thickness of the magnetic thin film can be suppressed, generation of eddy currents in the magnetic thin film can be prevented, and excellent magnetic properties can be ensured.

[Brief explanation of drawings]

FIG. 1 is a plan view of a composite magnetic head according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line E in FIG. 1, and FIG. 3 is a configuration of the first embodiment shown in FIG. An explanatory diagram illustrating the manufacturing process of the core half body, FIG. 4 is a plan view showing the main part of the second embodiment of the present invention, and FIG. 5 is a plan view showing the main part of the third embodiment of the present invention. FIG. 6 is a plan view showing the main parts of the fourth embodiment of the present invention, FIGS. 7 and 8 are explanatory diagrams of the fifth embodiment of the invention, and the IT diagram is a plan view showing the main parts. Figure 8 is A of Figure 7.
Fig. 9 is an explanatory diagram showing the problem when the radius of the valley of the core substrate shown in Fig. 7 is 5 μm or less, and Fig. 10 is an explanatory diagram showing the problem when the radius of the valley of the core substrate shown in Fig. 7 is A characteristic diagram showing the relationship between the size of the radius and the reproduction efficiency, Fig. 11 is a plan view showing the main parts of a conventional magnetic head, and Fig. 12 illustrates the manufacturing process of the core half of the magnetic head shown in Fig. 11. 21...Recording/reproducing head, 24,50.72.
...First core half, 25,53.73...
・IE2f half body, 29.32, 56.61.66.7
7゜78...Protrusion, 30,51.74...
... 1st: lA base, 31. 52. 81-...
・First magnetic thin film, 34°57.82...Second magnetic thin film, 35,55.76...Magnetic gap,
58.63... Core half, 59.64...
...Core base, 60.65...Slanted surface, 62.
67...Tip, 68.69...Magnetic thin film, 75...Second core base, 79.80...
···valley. Figure 1 2/: To the recording S student, 30.51, 74: 1st core base 3/, 52. Ell: Takunoishi Bon Korei Junyoko 33.5
4, 75: 2nd core F14 pieces 34.57, 82: 塘 2-Seiden ant, (5, 55, 76: Fry tip 5θ, 63: Core grass body 59.64: Fa series 60.65: 4 eaves side 62.67: Pigeon ω, 619: Compilation! Jf Tsuyuno, 80: Each Fig. 2, Fig. 3, 3H34) Fig. 7, Fig. 851J ts s. rψm)

Claims (2)

[Claims] (1) The first core half and the second core half are joined facing each other.
a magnetic gap at a joint between the first core half and the second core half;
Each of the core halves includes a core base and a magnetic thin film made of a magnetic material having a high saturation magnetic flux density and adhered to the side surface of the core base facing the magnetic gap, and the first core In a magnetic head, the side surface of the core base of at least one of the half body and the second core half body facing the magnetic gap is inclined with respect to the magnetic gap. A magnetic head characterized in that a protrusion made of a plurality of protrusions is provided on a portion of a core base having an inclined side surface facing the magnetic gap. (2) A magnetic head according to claim (1), wherein the radius of the valley of the protrusion formed in the protrusion is 15 μm or more.