JP2522228Y2 - Magnetic head - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head, and more particularly, to a magnetic head capable of effectively reducing external induction noise and simplifying and assembling a processing and assembling process.

2. Description of the Related Art In general, a magnetic head used in a magnetic recording / reproducing apparatus for recording / reproducing a magnetic disk has a composite head structure of a recording head and a reproducing head or a recording / reproducing head and an erasing head. FIGS. 6 to 8 show a conventional example of this type of magnetic head. FIG. 6 is a perspective view of the magnetic head 1, FIG. 7 is an exploded perspective view of the magnetic head 1, and FIG. 8 shows a state in which a shield material 2 is provided on the magnetic head 1 to reduce external induction noise. .

The magnetic head 1 comprises a magnetic head portion 3 and a slider 4.
And the like. The magnetic head part 3 has coils 5, 6
And a bridge bar 10 for closing the magnetic core 9 in a magnetic circuit. On the other hand, the slider 4 is composed of slider halves 4a and 4b made of a non-magnetic material (for example, ceramic) having a substantially L-shaped cross section.

In assembling the above components, the slider halves 4a and 4b are bonded and bonded to the magnetic core 9 using epoxy resin or glass, and then the sliding contact surface 11 facing the magnetic disk is polished. Next, the coils 5 and 6 constituting the magnetic circuit are connected to the magnetic core 9.
The magnetic head 1 shown in FIG. 6 is obtained by mounting a bridge bar 10 which is mounted on a magnetic head and forms a magnetic path. The shield member 2 is attached after the magnetic head 1 is formed.

However, in the conventional magnetic head 1 described above, when the magnetic core 9 and the slider halves 4a and 4b are bonded with epoxy resin or glass, it is necessary to position and join the components with high precision. However, since the slider halves 4a and 4b have an L-shaped cross section, they are unstable as they are, so it is necessary to hold them using a special jig until the adhesive is solidified, and the assembling work is troublesome. There was a problem. In addition, since the slider halves 4a and 4b are generally made of a rigid ceramic material containing TiBa or TiCa as a main component, it is difficult to process them into the L-shape shown in FIGS. 6 and 7. There was a problem. The shield member 2 has a ring shape made of, for example, permalloy. However, since the shield member 2 is attached after the magnetic head 1 is assembled, mounting workability is not good. In addition, the thickness of the shield member 2 is selected to be small in order to reduce the size of the magnetic head 1, and there is a problem that a sufficient shielding effect cannot be obtained. Further, as a method of attaching the magnetic head 1 to the polishing machine in the polishing step of the sliding contact surface 11, a method of bonding with a hot melt type wax or a method of mechanically chucking is considered. However, the former requires cleaning of the wax after processing, and the latter requires a jig. Neither method can use a chucking method using magnetic force (the slider 4 is ceramic and is not attracted by magnetic force). There was a problem.

In view of the above, an object of the present invention is to provide a magnetic head which solves the above-mentioned problem by forming at least a part of the slider with a magnetic material.

Means and Action for Solving the Problems In order to solve the above problems, in the present invention, a magnetic head portion provided with a magnetic gap and a coil, and a magnetic head portion holding the magnetic head portion and a recording medium are provided. A magnetic head provided with a slider portion for maintaining a sliding contact state, wherein a through hole is formed at a predetermined position of a block made of a ferrite material so as to surround at least the coil, and the magnetic head is provided on an upper surface of the block. And a shield portion having the same cross-sectional outer peripheral shape as the sliding contact surface shape of the slider portion facing the recording medium. It is a feature.

With the above-described configuration of the magnetic head, the slider portion and the shield portion have the same shape when the magnetic head is viewed from the sliding contact surface side with the recording medium, and the shield portion does not protrude to the outer periphery of the slider portion. The size can be reduced. Further, since the shield portion surrounds the coil, it is possible to prevent noise from being mixed into the recording / reproducing signal.

In addition, the ferrite material can be easily formed at a low cost because it can be easily formed and manufactured using a mold. Further, the shield portion has a configuration in which a through hole is formed only in a portion for storing the coil and the like, and since the area viewed from the sliding contact surface side is large, the shield portion is attached to a polishing machine used in the polishing process by a magnet. Chucking can be used. For this reason, the attachment / detachment to / from the polishing machine is facilitated, and a complicated jig is not required and an adhesive is not used, so that the cleaning step in the manufacturing process can be omitted.

Next, an embodiment of the magnetic head according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of the magnetic head 12 according to the present invention, and FIG. 2 is an exploded perspective view of the magnetic head 12. The magnetic head 12 is generally referred to as a magnetic head 1
3, the slider section 14, the shield section 15, and the like.

The magnetic head unit 13 has a well-known structure, and includes a magnetic core 18 having magnetic gaps 16 and 17 and coils 19 and 20 forming a magnetic circuit and a bridge bar 21 forming a closed magnetic circuit. ing. Of the above magnetic gaps 16 and 17,
One functions as a recording / reproducing magnetic gap, and the other functions as an erasing head. That is, the magnetic head unit 13
Is a composite structure.

The slider portion 14 is made of a non-magnetic ceramic, and is formed by cutting a plate having a simple structure having a size of, for example, 5 mm × 6 mm × 1 mm into a predetermined shape.
FIG. 2 shows a state in which the slider portion 14 is divided into two half portions 14a and 14b, but the corner portion is R-polished, the air groove 23 and the mounting groove 24 of the magnetic head portion 13 are formed. Is formed by attaching an unprocessed ceramic plate to the shield portion 15. Specifically, after a ceramic plate of a predetermined shape is bonded to the upper surface of the shield portion 15 with epoxy resin, the mounting groove 24 and the air groove 23 are simultaneously processed, and the corner portion is further R-polished to form the slider portion 14. Form. By the formation of the mounting groove 24, the slider portion 14 is substantially defined by the slider portion halves 14a and 14b. Since the slider portion 14 is formed after bonding a flat ceramic plate to the flat upper surface 15b of the shield portion 15, it is relatively easy to process the ceramic plate having a high hardness. it can. Further, since the ceramic plate can be used as it is, it can be easily processed.

The shield portion 15 is made of a sintered ferrite material which is a soft magnetic material, and is formed into a shape shown in FIGS. 1 and 2 by sintering using a mold. Specifically, it is formed in a shape having a cross-sectional shape substantially the same as the shape of the sliding contact surface 26 of the slider portion 14 facing the recording medium. The shield part 15 has a configuration in which a through hole 25 penetrated vertically is provided in a rectangular parallelepiped main body part 15a. The sintered ferrite material is easily formed and easily manufactured using a mold, and can be obtained at low cost. Further, since it is a soft magnetic material, a shielding effect can be obtained. In addition, in the forming process of the shield portion 15, the upper surface portion of the main body to which the slider portion 14 is adhered.
15b is polished with high precision.

 The procedure for assembling the above components will be described.

First, the magnetic core 18 is inserted into a mounting groove 24 formed in the slider section 14 adhered on the shield section 15. Then, the inserted magnetic core 18 is bonded to the slider section 14 with epoxy resin. At this time, since the slider portion 14 is already fixed to the shield portion 15, the conventionally required jig throwing is unnecessary, and the bonding operation can be easily performed.

Further, as described above, since the shield portion 15 has a cross-sectional shape substantially the same as the shape of the sliding contact surface 26 of the slider portion 14 facing the recording medium, the slider portion 14 and the shield member are bonded together. Reference numeral 15 has substantially the same shape when the magnetic head 12 is viewed from the side in contact with the recording medium. Therefore, the shielding member 15
However, the magnetic head 12 does not protrude from the outer periphery of the slider portion 14, and the size of the magnetic head 12 can be reduced as compared with the conventional configuration in which the shield member 2 is provided on the outer periphery of the slider portion 4 (see FIG. 8). The mounting groove 24 is configured to face the through hole 25. Therefore, when the magnetic core 18 is mounted on the slider portion 14, the coil mounting portions 18a, 18b and the central core portion 18c protrude into the through holes 25 formed in the shield portion 15.

Next, the magnetic gaps 16 and 17 of the magnetic core 18 to be the sliding contact surfaces 26
And the surface of the slider portion 14 are polished. At this time, the shield part 15 is made of a ferrite material, and the shield member 15 is provided only in a portion for storing the coils 19, 20 and the like.
5 is formed, and its volume is large (the area of the upper surface 15b is large), so that it can be attached to the polishing machine by magnetic attraction. Therefore, the magnet chucking can be performed, so that it can be easily attached to and detached from a processing machine. Further, since a complicated jig is not required and an adhesive is not used, a cleaning step can be omitted. After the completion of this polishing, the coils 19 and 20 are attached to the coil mounting portions 18a and 1 from the back side of the shield portion 15.
The magnetic head 12 shown in FIG. 1 is formed by attaching the bridge bar 21 to the bridge bar 21 and then attaching the bridge bar 21 thereto.

The assembling procedure is not limited to the above. For example, before bonding a ceramic plate serving as the slider portion 14 to the shield portion 15, the slider portions 14a and 14b are prepared in advance and divided into the slider portion halves 14a. , 14b, shield part 15, magnetic core 1
The eight parts may be combined and joined together.

Here, the magnetic head 12 is a magnetic recording / reproducing device (not shown)
FIG. 3 shows a cross section of the magnetic disk 27 mounted on the magnetic disk 27 in sliding contact therewith. FIG. 3 shows a configuration in which a pair of magnetic heads 12 are in sliding contact with both surfaces while holding the magnetic disk 27 therebetween. As shown in the figure, most of the coils 19 and 20 and the magnetic core 13 are surrounded by a shield part 15 formed of a ferrite material which is a soft magnetic material. Therefore, the externally induced noise is reliably blocked by the shield part 15, so that the magnetic circuit composed of the magnetic core 13 and the coils 19 and 20 is not affected by the induced noise, and good magnetic recording and reproduction can be performed. Can do it. In addition, as shown in FIG.
Needless to say, a configuration in which 12 is in sliding contact with each other is also possible. In the figure, reference numeral 28 denotes a pad for improving the state of sliding contact between the magnetic head 12 and the magnetic disk 27.

Next, another embodiment of the magnetic head according to the present invention is shown in FIG. The magnetic head 29 shown in the figure has a shield portion 30 having a stepped shape, a part of which is extended upward to form an extension portion 30a.
Are configured to be able to slide on the magnetic disk 27. As shown in the figure, by configuring the pair of magnetic heads 29 so that each magnetic gap is positioned so as to face the extension 30a and clamp the magnetic disk 27, the magnetic core 18 functions as a main magnetic pole, In addition, the extension portion 30a can function as an auxiliary magnetic pole, and this magnetic head 29 can be used for a perpendicular magnetic recording system. With the above configuration, high-density recording can be realized by the magnetic head 29 having a simple configuration.

Further, all members surrounding and holding the magnetic head may be made of a ferrite material. In this case, a mounting groove is formed in a molded product of a sintered ferrite material to be a slider having a substantially U-shaped cross section, and a magnetic head portion is inserted and adhered to the mounting groove to form a magnetic head. At this time, if the ferrite material approaches or comes into contact with the magnetic gap of the magnetic head, there is a possibility that a magnetic field leak occurs and the characteristics are deteriorated. Therefore, in the magnetic head having the above configuration, an adhesive layer or a nonmagnetic material such as glass, ceramic, or plastic is interposed between the magnetic head portion and the ferrite material, and a gap of 0.05 mm to 0.3 mm is formed therebetween. There is a need to. In the magnetic head having this configuration, since almost all the outer peripheral portion of the magnetic head portion is surrounded by the ferrite material, which is a soft magnetic material, external induction noise can be more reliably blocked and the S / N ratio is improved. Can be.

Effect of the Invention As described above, according to the magnetic head of the present invention, since the slider portion and the shield member are configured to have substantially the same shape when viewed from the sliding contact surface side, the shield member protrudes to the outer periphery of the slider portion. Therefore, the size of the magnetic head can be reduced, the cost can be reduced by using an inexpensive magnetic material such as a sintered ferrite material as the material of the shield member, and the through hole can be provided at a predetermined position. By using a ferrite material formed with a magnetic layer, chucking using magnetic attraction can be performed in the polishing process of the sliding contact surface, and the attaching and detaching work of the magnetic head at the time of processing can be facilitated, and in addition to this, a complicated Cleaning of jigs and adhesives is not required, and the magnetic head has a structure surrounded by magnetic material. Improvement can be achieved, and good magnetic recording and reproduction can be performed.

[Brief description of the drawings]

FIG. 1 is a perspective view of an embodiment of the magnetic head according to the present invention,
FIG. 2 is an exploded perspective view of the magnetic head shown in FIG. 1, FIG. 3 is a view showing a use mode in which a pair of magnetic heads are arranged so as to sandwich the magnetic disk, and FIG. FIG. 5 shows a magnetic head having a configuration in which a part of a shield portion is extended so as to be in sliding contact with a magnetic disk, and FIG. 6 is an example of a conventional magnetic head. 7, FIG. 7 is an exploded perspective view of the magnetic head shown in FIG. 6, and FIG. 8 is a perspective view showing a state where a shield material is attached to the magnetic head shown in FIG. 12, 29: magnetic head, 13: magnetic head, 14: slider, 14a, 14b: half of slider, 15, 30, ... shield, 18
... magnetic core, 19, 20 ... coil, 24 ... mounting groove, 25 ... through hole, 27 ... magnetic disk.

Claims (1)

(57) [Scope of request for utility model registration] 1. A magnetic head comprising: a magnetic head portion provided with a magnetic gap and a coil; and a slider portion holding the magnetic head portion and maintaining a predetermined sliding contact with a recording medium. A through hole is formed at a predetermined position of a block made of a material to surround at least the coil, and the magnetic head unit and the slider unit are placed and fixed on the upper surface of the block, and A magnetic head, wherein a shield portion having the same cross-sectional outer peripheral shape as the sliding contact surface shape of the slider portion facing the recording medium is provided on the slider portion.