JP2995815B2 - Magnetic head - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head mounted on a hard disk drive or the like, and more particularly, to an improvement in winding processing of a magnetic head having a monolithic structure.

[Summary of the Invention]

According to the present invention, in a magnetic head having a monolithic structure, a winding for winding is provided by providing a winding winding groove on a magnetic gap forming surface of one ferrite core and embedding a spiral winding in this groove. The purpose is to make the work easier and to make the head thinner.

[Conventional technology]

A magnetic head that performs recording and reproduction on a so-called hard disk needs to be floated at a very small distance with respect to the disk surface during recording and reproduction, and is generally integrated with a slider.

Therefore, as a magnetic head for a hard disk so far, a monolithic structure head in which the entirety including a slider is integrally formed of a ferrite material or the like, a composite type head in which a magnetic head separately manufactured in a slider is embedded, Further, a thin film head formed by a vacuum thin film forming technique has been developed.

Among them, a magnetic head having a monolithic structure (hereinafter, referred to as a monolithic head) is widely used because of its low manufacturing cost and high reliability. For example, as shown in FIG. 5, a winding groove (5) is formed on a magnetic gap forming surface (52) of a wide ferrite core (51) which also functions as a slider, as shown in FIG.
The ferrite core (54) on which 3) is formed is joined, and a magnetic gap g is formed on the abutting surface.

In the monolithic head, after a ferrite core (54) having a winding groove (53) formed on a magnetic gap forming surface (52) of a wide ferrite core (51) is joined and integrated, the winding groove (53) is formed. It is manufactured by winding a winding (55) around the wire. In this type of head, the core height T is generally about 1.27 mm. However, as the driving device on which this head is mounted becomes thinner, a reduction in the core height T is required. It is becoming.

However, when the core height T is reduced, the wire diameter of the winding (55) must be reduced.
It becomes difficult to automate the winding operation. Further, if the core height T is simply reduced, the area of the winding groove (53) cannot be secured because the core cross-sectional area is reduced. Therefore, at present, the core height T is limited to about 0.87 mm, and it is no longer possible to cope with further reduction in the thickness of the driving device.

[Problem to solve the invention]

In view of the above, the present invention has been proposed in view of the above-described conventional circumstances, and provides a magnetic head which can easily perform a winding operation of a winding and has excellent magnetic characteristics capable of being thinned. Aim.

[Means for solving the problem]

In order to achieve the above-mentioned object, the present invention provides a first ferrite core which also functions as a slider, in which a groove for winding winding is formed on a magnetic gap forming surface, and a spiral winding is formed in the groove. The wire is buried and flattened, and a second ferrite core is joined to the magnetic gap forming surface, and the width of the spiral winding is made larger than the width of the second ferrite core. It is characterized by having.

Further, according to the present invention, a groove for winding the winding is formed on the magnetic gap forming surface of the first ferrite core which also functions as a slider, and a spiral winding is embedded in the groove to be flattened. In addition, a second ferrite core provided with a winding groove corresponding to the winding groove is joined to the magnetic gap forming surface, and the depth of the magnetic gap is regulated by the winding groove. It is characterized by having.

[Action]

In the present invention, a groove for embedding a winding is provided on the magnetic gap forming surface of the first ferrite core which also functions as a slider, and the winding is wound in this groove in a spiral shape by plating or the like. The wire can be wound in a flat state, and the winding operation of the winding can be easily performed.

Further, since it is not necessary to wind a winding around the winding groove of the other ferrite core, the size of the winding groove can be made small, and a reduction in the height of the core can be expected.

〔Example〕

Hereinafter, specific embodiments to which the present invention is applied will be described with reference to the drawings.

In order to fabricate the magnetic head of this embodiment, first, as shown in FIG. 1A, a magnetic gap forming surface (1a) of a first ferrite core (1) which also functions as a slider is provided.
A plurality of winding grooves (2) for embedding windings to be described later are formed corresponding to the number of magnetic head elements.

In the present embodiment, the winding groove (2) is formed around the periphery thereof except for a rectangular connection part (3) for magnetically connecting to a second ferrite core described later in the center. Was formed in a substantially rectangular shape in a plane with a certain depth, and both ends of one side edge of the groove (2) were expanded outward. Portions provided at both ends of one side edge of the groove (2) are used as terminal portions for leading out terminals of a winding described later.

In order to form the groove (2) for winding the winding, a method using an NC processing machine or a so-called powder beam processing method in which etching is performed by spraying fine particles (polishing powder), etc., may be used.
In the present example, a portion other than the portion to be grooved was masked with a resist by a powder beam processing method, and then fine particles were sprayed to perform the groove processing.

Next, an insulating film (not shown) is formed over the entire surface of the magnetic gap forming surface (1a) including the inside of each of the winding grooves (2).

Note that, when the first ferrite core (1) has a high insulating property, or when a later-described winding is formed of a wire having an insulating coating, the insulating winding is not necessarily required.

Next, as shown in FIG. 1 (B), a winding (4) is formed in a spiral shape in the groove (2).

In this example, a conductive material such as Cu was vapor-phase plated and then etched to form a spiral shape. Alternatively, a normal wire may be wound around the connection portion (3) so as to surround the connection portion.

Then, the winding start portion (4a) and the winding end portion (4b) of the winding (4) are led out to both ends of one side edge of the groove (2), and this is used as a terminal portion.

As described above, since the winding step can be performed in a planar state, the winding operation is extremely easy, and the batch processing can be performed, so that cost reduction can be expected.

Next, as shown in FIG. 1C, an insulating film is formed on the winding (4), and a winding (5) similar to the winding (4) is further formed on the insulating film. Is formed in a spiral shape.

At this time, the winding end (5b) of the winding (5) formed above and the winding start (4a) of the winding (4) provided below are connected, and these windings (4), ( 5) is performed in series to secure the number of turns of the winding.

And the winding start part (5a) of these windings (4) and (5)
Then, pads (6a) and (6b) made of conductors are provided on the winding end portion (4b), respectively, and these are used as terminals.

Next, the grooves (2) for winding each winding are filled with an insulating material (not shown), and the magnetic gap forming surface (1a) is formed.
Is flattened.

The flattening here is performed by polishing, and the purpose is to obtain the flatness of the magnetic gap forming surface (1a).

The terminal of the winding (5) filled with the insulating material is taken out to the magnetic gap forming surface (1a) by wire bonding or the like.

Next, a gap film (not shown) is formed over the entire surface of the magnetic gap forming surface (1a).

In FIG. 1 (C), the insulating material and the gap film filling the groove (2) for winding the winding are shown as transparent so that the winding (5) can be seen as being wound. It is.

Next, as shown in FIG. 1 (D), each of the winding grooves (2) of the second ferrite core (7) constituting the magnetic circuit portion with the first ferrite core (1). The comb-tooth portions (8) constituting the magnetic head elements are formed at positions corresponding to ()).

The comb tooth portion (8) cuts a winding groove (9) for controlling the depth of the magnetic gap at a portion corresponding to a portion between the front gap portion and the connection portion (3) of the first ferrite core (1). By processing, a front part (8a) connected to the front gap part and a back part (8a) connected to the connection part (3) are formed. The groove (10) for forming the comb teeth (8) and the groove (11) for forming the back part (8a) are both cut to positions at least at least the core thickness.

Next, the second ferrite core (7) is glass-fused and joined to the magnetic gap forming surface (1a) of the first ferrite core (1).

When joining the second ferrite core (7),
The front part (8a) of each comb tooth (8) is aligned with the front gap part of the first ferrite core (1), and the back part (8b) is connected to the connection part (1) of the first ferrite core (1). Align to 3).

As a result, the back portion (8b) is surrounded by the winding (5), and the winding is wound around the winding groove as in a normal head.

Next, polishing is performed from the back surface (7a) opposite to the bonding surface of the second ferrite core (7) to a position where a desired core thickness is obtained toward both bonding sides.

In this example, the polishing was performed to at least a position reaching the groove (10) for forming the comb tooth portion (8) and the groove (11) for forming the back portion (8a).

As a result, the comb teeth (8) are cut off, and as shown in FIG. 1 (F), magnetic head elements (12) each having a magnetic gap g formed on the glass-fused joint surface are formed. .

Then, the first ferrite core (1) is sliced at the positions indicated by the lines AA and BB in FIG. 1 (F) to cut out the magnetic head.

Next, as shown in FIGS. 2 and 3, the magnetic head is subjected to depth processing for regulating the depth of the magnetic gap g, rail processing for introducing a flow of air to obtain a stable flying state, and Track processing is performed to set the track width of the gap g.

Depth processing is performed by flat processing the hard disk facing surface (1b).

In the rail machining, steps are provided on both sides of the track portion of the magnetic gap g over the longitudinal direction of the first ferrite core (1). The rail groove (13) formed by this step serves to introduce airflow between the hard disk facing surface (1b) and the hard disk during driving, and to float the hard disk with a small gap.

In the track processing, a resist is provided on both sides of a track portion to be formed, and the resist is processed by the above-described etching using fine particles by using the resist as a mask.

This allows the magnetic gap g to have a predetermined track width.
It is called Tw.

According to the so-called powder beam processing method by spraying the fine particles, since the fine dimensional accuracy in the depth direction is excellent, the depth control can be performed with high accuracy, and the winding (5) can be positioned near the depth. .

In this head, the tip side of the magnetic core divided by the second ferrite core (7) was tapered to form an inclined surface (7a) so as not to damage the hard disk surface during driving.

The monolithic head manufactured as described above,
A closed magnetic path is formed by a magnetic core cut out by the first ferrite core (1) and the second ferrite core (7), and a magnetic gap g is formed on a magnetic gap forming surface (1a) which is a joining surface of these magnetic cores. Is formed,
The second ferrite core (1) also has a function as a slider. In particular, in this head, the windings (4) and (5) are embedded in the magnetic gap forming surface (1a) of the magnetic core cut out from the first ferrite core (1) which also functions as a slider. Therefore, it is not necessary to wind the winding around the winding groove (9) of the other magnetic core as in the prior art. Therefore, complicated winding work of the winding can be omitted, and the size of the winding groove (9) can be reduced, whereby the core thickness C can be reduced. Even if the core thickness C is reduced, the winding groove (9)
Because the size of the magnetic core is not restricted, the front part (8) of the magnetic core cut out from the second ferrite core (7)
Since the core cross-sectional area of a) and the back part (8b) can be sufficiently secured, the output characteristics do not deteriorate. As described above, in the head of the present example, it is expected that the thickness is reduced. Therefore, the volume per unit thickness of the slider is reduced, the inductance per one winding is reduced, and the magnetic characteristics in which noise is suppressed in a high frequency region are reduced. The magnetic path length is shortened and the magnetic efficiency is improved.

〔The invention's effect〕

As is clear from the above description, in the present invention, a groove is formed on the magnetic gap forming surface of the ferrite core which also functions as a slider, and the winding is formed in a spiral shape in this groove. Becomes extremely easy.

Further, according to the magnetic head of the present invention, since it is not necessary to wind a winding around the winding groove, it is possible to reduce the size of the winding groove while securing the core cross-sectional area. The height can be reduced. Therefore, it is possible to reduce the thickness of the head while maintaining the magnetic characteristics, and it is possible to sufficiently cope with the reduction in the thickness of the driving device.

[Brief description of the drawings]

1 (A) to 1 (F) are schematic perspective views showing an example of a method of manufacturing a magnetic head to which the present invention is applied, in the order of steps, and FIG. 1 (B) is a winding step, FIG. 1 (C) is a flattening step, FIG. 1 (D) is a second ferrite core manufacturing step, FIG. 1 (E) ) Shows the joining step, and FIG. 1 (F) shows the dividing step. 2 to 4 show an example of a monolithic magnetic head to which the present invention is applied. FIG. 2 is an enlarged perspective view showing the whole, FIG. 3 is an enlarged front view, and FIG. It is an expanded sectional view. FIG. 5 is a side view showing a conventional monolithic magnetic head. DESCRIPTION OF SYMBOLS 1 ... 1st ferrite core 1a ... Magnetic gap formation surface 2 ... Groove for winding winding 4,5 ... Winding 7 ... 2nd ferrite core 8 ... Comb part 9 ... Winding Wire groove

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 5/127-5/17

Claims (3)

(57) [Claims] A first ferrite core which also functions as a slider, a winding groove is formed on a magnetic gap forming surface of the first ferrite core, and a spiral winding is buried in the groove to be flattened; A magnetic head, wherein a second ferrite core is joined to the magnetic gap forming surface, and a width of the spiral winding is larger than a width of the second ferrite core. . 2. The magnetic head according to claim 1, wherein terminal portions at both ends of the spiral winding are exposed to the outside on a magnetic gap forming surface of the first ferrite core. 3. A winding groove is formed on a magnetic gap forming surface of a first ferrite core also functioning as a slider, and a spiral winding is buried in the groove to be flattened. A second ferrite core provided with a winding groove corresponding to the winding groove is joined to the magnetic gap forming surface, and the depth of the magnetic gap is regulated by the winding groove. A magnetic head.