JPH04188426A - Magnetic head - Google Patents

Abstract

PURPOSE:To enable high-density recording by mounting a non-magnetic section at a specified position of a slider so as to reduce the sectional area of magnetic flux path at a position where the magnetic circuit of the slider is formed. CONSTITUTION:The end section 47 of a slider 29 is projected from a surface 49 on the side reverse to a flying surface 33, and a non-magnetic member 51 is set up on the surface 49 through glass bonding. A notch 53 matched with the end section 47 is formed in the non-magnetic member 51, and the non- magnetic member 51 is fast stuck onto the whole surface of the surface 49 of the slider 29 because the end section 47 is inserted into the notch 53. The relationship of x>=y holds in size (x) in the left and right direction of a core 34 and size (y) in the same direction of the end section 47 of the slider 29 at that time, and the relationship of m<=n holds in size (m) in the vertical direction of the lower end section 45 of the core 34 and size (n) in the same direction of the end section 47 of the slider 29. The sectional area at a C section, i.e., the path of magnetic flux 25, is throttled by holding such dimensional relationship. Accordingly, the inductance of a coil can be reduced without decreasing the number of turns of the coil, and deterioration of S/N ratio representing magnetic recording characteristics can be prevented.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application Field) This invention provides a slider that floats a small amount relative to a recording medium, and a coil that is wound by forming a magnetic gap between the slider and the slider. The present invention relates to a magnetic head that forms a magnetic circuit with a core through which magnetic flux passes.

(Prior Art) A magnetic disk drive, which is used as an external storage device for a computer, applies the dynamic pressure of air to a rotating magnetic disk, which is a recording medium, while being pressed with a predetermined load by a support spring mechanism called a suspension. Recording and reproduction are performed with the magnetic head slightly floating due to this effect.

6 and 7 are a side view and a plan view from the magnetic disk 5 side showing a magnetic head assembly in which the magnetic head 1 is attached to the tip of the suspension 3. FIG.

The suspension 3 is made of a stainless steel plate spring with a thickness of about 50 to 70 μm, and applies a load (6.0 to 9°5 g f) to the magnetic head 1, and the suspension 3 has a magnetic field at its tip when it is levitating. The magnetic head 1 is attached via a gimbal spring 7 for keeping the attitude of the head 1 stable. The gimbal spring 7 has a magnetic head].

A protrusion is provided to concentrate the load on one point. A mount 9 is provided on the base side of the suspension 3 for fixing the magnetic head assembly to a carriage arm (not shown) of a voice coil motor for causing a seek operation of the magnetic head with respect to the magnetic disk 5. It is being

As shown in FIG. 8, which is a perspective view seen from the magnetic disk 5 side, the magnetic head 1 includes a slider 11 that floats a small amount with respect to the magnetic disk 5, and a magnetic disk 5 of the slider 11.
Core 13 provided on the front end side in the rotation direction (direction of arrow A)
It is equipped with This magnetic head 1 is called a monolithic type in which both the slider 11 and the core 13 are made of a magnetic material such as Mn--Zn ferrite. An air bearing surface 15 is formed on the surface of the slider 11 facing the magnetic disk 5, a coil 17 is wound around the core 13, and a magnetic gap 19 is formed between the slider 11 and the core 13. The coil 17 is drawn out to the carriage arm via the suspension 3, and is protected by the tube 2 near the top of the suspension 3.

In such a magnetic head 1, when recording information on the magnetic disk 5, by passing a current through the coil 17, a magnetic flux 25 is generated across the core 13 and the slider 11 as shown in FIG. is formed, and magnetic recording is performed on the magnetic disk 5 by the leakage magnetic flux of this magnetic flux 25 at the magnetic gap 19. When reproducing information recorded on the magnetic disk 5, the magnetic gap 19 captures the magnetic flux generated on the magnetic disk 5, and a magnetic flux 25 is generated across the core 13 and the slider 11 as shown in FIG. A magnetic circuit is formed, a current is generated in the coil 17 in response to this, and a reproduced signal is obtained.

(Problem to be solved by the invention) Incidentally, the storage capacity of the magnetic disks used in recent magnetic disk devices has tended to become more and more dense, and as a result of this, the reproduction output of the magnetic head has inevitably become smaller. becomes. As a countermeasure for this, a larger reproduction output can be obtained by increasing the number of turns of the coil wound around the core, but this also increases the inductance of the coil.

The inductance of the coil is S(
There is a proportional relationship with the noise in the signal)/N (noise) ratio. Therefore, as the inductance increases, the noise increases and the S/N ratio deteriorates. Furthermore, this inductance tends to increase as the cross-sectional area of the magnetic flux path increases. Therefore, when the entire slider 11 is made of magnetic material and the magnetic flux 25 passes through it as shown in FIG. 9, the inductance becomes large. The noise will increase.

Therefore, this invention suppresses the inductance of the coil in the magnetic head to a low level without reducing the number of turns of the coil.
The purpose is to enable high-density recording.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above-mentioned problems, this invention forms a magnetic gap between a slider that floats a small amount by an air flow with respect to a recording medium, and this slider. In the magnetic head, the magnetic head includes a core around which a coil is wound, and forms a magnetic circuit through which a magnetic flux passes between the core and the slider. A non-magnetic portion is provided at a predetermined portion of the magnetic head.

(Function) In the magnetic circuit formed between the core and the slider, the cross-sectional area of the magnetic flux on the slider side is reduced by providing the non-magnetic portion, so the inductance of the coil wound around the core is small. .

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a sectional view of a magnetic head used in a magnetic disk device showing one embodiment of the present invention, and FIG. 2 is a perspective view of the same magnetic head. This magnetic head 27 has a slider 29
Two grooves 31 are formed along the direction of rotation of the magnetic disk shown by arrow B on the surface facing the magnetic disk (not shown), and an air bearing surface 33 for the magnetic disk is formed on the outside of these grooves 31. A core 34 is provided at the front end in the rotational direction. This magnetic head 27 includes a slider 29 and a core 3, similar to that shown in FIG.
4 is a monolithic type made of magnetic material such as Mn-Zn ferrite. A magnetic gap 37 is formed between the two rails 35 of the slider 29 and the core 34, and a coil 39 is wound around the core 34. The core 34 is formed into a substantially C-shape, and in FIG. The end portion 45 is joined to an end portion 47 of the slider 29 on the side opposite to the air bearing surface 33 .

The end portion 47 of the slider 29 projects downward in FIG. 1 from a surface 49 opposite to the air bearing surface 33.
A non-magnetic member 51 made of ceramic or the like, which is a non-magnetic part, is attached by glass bonding, which is bonded by melting glass. The non-magnetic member 51 has a notch 53 aligned with the end 47 as shown in FIG.
is formed, and the end portion 47 enters the notch 53, so that the non-magnetic member 51 is brought into close contact with the entire surface 49 of the slider 29.

Here, in FIG. 1, the dimension X in the left-right direction of the core 34 and the dimension y in the same direction of the end portion 47 of the slider 29 are X.
There is a relationship of ≧y, and a relationship of m≦n between the dimension m of the lower end portion 45 of the core 34 in the vertical direction in the drawing and the dimension n of the two slider end portions 47 in the same direction. With such a dimensional relationship, the cross-sectional area of the 0 section, which is the path of the magnetic flux 25, is narrowed down, and as a result, the inductance of the coil 39 can be reduced without reducing the number of turns of the coil 39, and S, which represents the magnetic recording characteristics, can be reduced. /N ratio is prevented from decreasing. Further, since it is not necessary to reduce the number of turns of the coil 39 in order to reduce the inductance, a reduction in the reproduction output is suppressed and maintained at a desired level.

4 and 5 show other embodiments of the invention. The magnetic head 55 in this embodiment has a slider 57
In order to narrow down the cross-sectional area of the magnetic flux passage in the 0 section, a slit 61 extending in a direction perpendicular to the paper plane in FIG. 4 is formed near the end of the back surface 59 of the slider 57 on the side of the core 34.
A non-magnetic member 63 made of glass serving as a non-magnetic portion is embedded in this slit 61. The rest of the structure is similar to the embodiment shown in FIG. 1, and the same components as in FIG. 1 are given the same reference numerals. In this case, the dimensional relationship of each part is the same as in FIG. The inductance is reduced, and the same effect as in the embodiment shown in FIG. 1 is achieved.

Furthermore, this embodiment has the advantage of being easier to manufacture than the embodiment shown in FIG. 1, since it is only necessary to form the slit 61 and embed the non-magnetic member 63.

[Effects of the Invention] As explained above, according to the present invention, the passage cross-sectional area of the magnetic flux on the slider side in the magnetic circuit formed between the core and the slider is smaller due to the non-magnetic portion. The inductance of the coil can be reduced without reducing the number of turns, and the S/N that represents magnetic recording characteristics
It is possible to prevent the ratio from decreasing. Further, since it is not necessary to reduce the number of turns of the coil in order to reduce the inductance, the reduction in reproduction output can be suppressed and maintained at a desired level.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a magnetic head showing one embodiment of the present invention, FIG. 2 is a perspective view thereof, FIG. 3 is a perspective view of a non-magnetic member, and FIG. 4 is a diagram showing another embodiment of the invention. 5 is a perspective view of the magnetic head, FIG. 6 is a side view of a magnetic head assembly using a conventional magnetic head, FIG. 7 is a plan view of the same magnetic head assembly, and FIG. 8 is a cross-sectional view of the magnetic head. FIG. 9 is a perspective view of the magnetic head, and FIG. 9 is a sectional view of the magnetic head. 25...Magnetic flux 27.55...Magnetic head 29.
57...Slider 34...Core 37...Magnetic gap 39...Coil 51, . 63...Nonmagnetic member

Claims (1)

[Claims] A slider that floats a small amount by an air flow with respect to a recording medium, and a core around which a coil is wound with a magnetic gap formed between the slider and a magnetic circuit in which a magnetic flux passes between the core and the slider are formed. 1. A magnetic head, characterized in that a non-magnetic portion is provided at a predetermined portion of the slider so as to reduce a cross-sectional area of a magnetic flux path in a portion of the slider forming a magnetic circuit.