JP3277268B2 - Floating magnetic head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floating magnetic head used in a magnetic disk drive.

[0002]

2. Description of the Related Art As an example of a conventional floating magnetic head,
As shown in JP-A-6-20245, a slider having a coil groove for accommodating a triangular coil at a corner is provided, and a recording / reproducing head core is joined to a side surface at one end of the slider. There is something. In this floating type magnetic head, the coil wound around the head core is housed in the coil groove so as not to interfere with the slider.

[0003] In recent years, magnetic disk drives have been increasing in density and miniaturization, and floating magnetic heads used in magnetic disk drives have also been reduced in size.
The volume occupied by the coil (winding) is considerably large with respect to the size of the head core, and a large space is required as a groove for the coil. The air bearing surface of the slider (the surface facing the magnetic recording medium) and the coil There is a tendency to reduce the thickness between the grooves. For this reason, when a mechanical force acts during assembling and processing operations of the floating magnetic head, there is a problem that the slider and the magnetic head core are easily damaged or broken.

As a solution to the above problem, there is a floating magnetic head proposed by the present applicant in Japanese Patent Application No. 7-224775. As shown in FIGS. 5 and 6, one end of a slider 4 having first and second rails 2 and 3 for generating a floating force on a magnetic recording medium (not shown), as shown in FIGS. (Hereinafter, this one end is referred to as the trailing side 5 and the other end is referred to as the leading side 6 as appropriate.)
And a recording / reproducing head core 7 joined to the side surface of the first member. The slider 4 is composed of first and second bodies 4A and 4B made of nonmagnetic ceramics joined to each other.
A concave groove 8 extending in the longitudinal direction is formed on the joint surface side of the body 4A with the second body 4B, and the second body 4B is joined to the first body 4A so as to cover the concave groove 8. Let me.

[0005] The second body 4B is joined to the first body 4A so as to cover the concave groove 8 in a substantially plate-like shape, leaving a plate-like edge 9 on the trailing side 5. Two rectangular through holes (coil holes) 10 and 11 facing the concave groove 8 are formed. Hereinafter, the through hole 10 on the trailing side 5 and the through hole 11 on the leading side 6 are referred to as a trailing side through hole 10 and a leading side through hole 11, respectively. A plate-like bridge portion 12 is formed between the trailing-side through hole 10 and the leading-side through hole 11 so as to be substantially parallel to the edge 9.

The air bearing surface 13 of the second body 4B
The side (the side facing the magnetic recording medium) constitutes the second rail 3 together with the part of the first body 4A on the side of the air bearing surface 13 on the side of the joint surface of the head core 7.

[0007] A head core 7 is joined to a side surface 4a of the trailing side 5 of the second body 4B. The head core 7 has legs (hereinafter, first and second legs 14,
15 ) Having a pair of substantially C-shaped first and second core bodies 16 and 17 having first and second legs 14 and 15.
Are formed in a substantially annular shape with their ends joined so as to face each other. Air bearing surface 13 of head core 7
A magnetic gap 18 for recording / reproducing is formed at the joint on the side. The head core 7 includes first and second legs 14, 1
5 is joined to the side surface portion 4a of the second body 4B with the edge portion 9 and the bridge portion 12 facing each other. Then, the edge portion 9 and the first leg portion 14, and the bridge portion 12 and the second
The conductors 19 are wound around the legs 15 of the
A, 20B are formed. Both coils 20A, 20B
Are so-called balanced windings connected so as to cancel an external magnetic field.

In this floating type magnetic head 1, the slider 4 is formed by joining the second body 4B so as to cover the groove 8 of the first body 4A, so that the groove 8 is formed. The second body 4B compensates for the decrease in strength, thereby improving the strength of the slider 4, and increasing the bonding area of the head core 7 to improve the adhesive strength.
And the head core 7 can be prevented from being damaged.

[0009]

However, in the above-described prior art, the coil 20A formed by winding the conductor 19 around the first leg 14 and the edge 9 of the head core 7 projects outside the slider 4. And the coil 20A
The coil 20A comes into contact with the magnetic recording medium when the slider 4 has a small floating amount on the magnetic recording medium, for example, as shown in FIG. As a result, there is a problem that the crash of the floating magnetic head 1 may damage the head core 7 or destroy data on the magnetic recording medium.

In order to solve the above-mentioned problem caused by the coil 20A being unwound, for example, as shown in FIG. 8, a plastic bobbin 21 is mounted on the head core 7 and the coils 20A and 20B are sandwiched between flanges 22 formed on both ends thereof. It is conceivable to prevent the coil 20A from being wound around the air bearing surface 13 side. However,
When the plastic bobbin 21 is mounted on the head core 7 in this way, the arrangement space of the coils 20A and 20B is limited, and it becomes difficult to arrange coils having a desired number of turns. Further, since the plastic bobbin 21 is easily deformed, the flange 22 is widened by the coil 20A and protrudes from the air bearing surface 13 of the slider 4, and there is a possibility that the slider 4 may be damaged or broken when floating. In addition, the mounting of the plastic bobbin 21 has a problem that the number of components increases, the number of bobbin mounting steps increases, and the cost of the apparatus increases.

Further, with the increase in the density of the magnetic disk drive described above, the holding power of the magnetic recording medium has been increased, and the gap length of the head core 7 has been reduced. Therefore, it is necessary to improve the magnetic efficiency of the head core 7. is there. In order to improve the magnetic efficiency of the head core 7, for example, in the floating magnetic head 1 shown in FIGS. 5 and 6, the head core 7 may be brought as close as possible to the magnetic gap 18 to reduce the amount of leakage magnetic flux. However, when the groove 8 formed in the slider 4 is moved closer to the air bearing surface 13 in order to bring the coil closer to the magnetic gap 18, the coil 20 A is unwound and easily projects to the air bearing surface 13. There is a limit in approaching to the side, and the fact is that the reduction in the amount of leakage magnetic flux and, consequently, the improvement in the efficiency of the head core 7 are restricted.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to prevent a magnetic head from being damaged by preventing a coil from being unwound and to prevent data from being destroyed on a magnetic recording medium, and to improve magnetic efficiency. It is an object of the present invention to provide a type magnetic head.

[0013]

SUMMARY OF THE INVENTION The present invention relates to a floating type magnetic head in which a recording / reproducing head core is joined to one side surface of a slider having a rail for generating a floating force on a magnetic recording medium. Are composed of first and second bodies made of nonmagnetic ceramics joined to each other,
A groove is formed on a joint surface side of the first body with the second body, and a plate-like edge to which a leg of the head core is joined is left on the second body to which the head core is joined. A notch is formed at one end of the edge of the second body so that a coil hole for accommodating the coil is formed together with the groove, and the edge of the second body has a substantially U-shape in a front view. Features. In this case, instead of the notch formed so that the edge of the second body is substantially U-shaped when viewed from the front, the second body is formed so that the edge of the second body is inverted L-shaped when viewed from the front. A notch may be formed at one end of the edge of the edge.
With the above-described configuration, the rail-side flange formed at the edge of the second body suppresses deformation of the coil toward the rail, thereby preventing the coil from being unwound.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A floating magnetic head 1 according to an embodiment of the present invention will be described below with reference to FIGS.
Description and illustration of members and portions equivalent to those shown in FIGS. 5 and 6 will be omitted as appropriate. In the floating magnetic head 1 according to the present embodiment, the trailing side through hole 10 and the leading side through hole 11 are provided to be shifted from the leading side 6 by a predetermined dimension as compared with those shown in FIGS. As a result, the edge 9 is formed wide, and the bridge portion 12 is formed shifted to the leading side 6.

In FIG. 1, the edge 9 of the second body 4B is shown.
Is formed at one end of the second body 4B so that the edge 9 has a substantially U-shape in a front view.
The edge 9 of the head core 7 joins the first leg 14 of the head core 7 to form a coil 20 with the first leg 14 as shown in FIG.
Edge main body 24 around which A is wound, and both ends of the edge main body 24 (the end on the air bearing surface 13 side end and the opposite end)
The first and second flanges 25 and 26 are formed to protrude outward (left side in FIG. 1). The coil 20A is wound around the first leg 14 and the edge main body 24 as shown in FIG. FIG.
S is a coil (winding) 20 from the air bearing surface 13
Shows the distance to A. The distance S is changed by adjusting the thickness of the first flange 25, and corresponds to the thickness of the first flange 25.

In the above-mentioned floating magnetic head 1, the coil 20A wound around the first leg 14 and the edge main body 24 is used.
Is sandwiched between the first and second flange portions 25 and 26, so that the first and second flange portions 25 and 26 suppress the deformation of the coil 20A and prevent the coil 20A from becoming loose. Therefore, the coil 2
0A is prevented from dropping to the air bearing surface 13 of the slider 4, and even if the flying height of the slider 4 on the magnetic recording medium is small, the coil 20A does not come into contact with the magnetic recording medium. Head core 7
Of the magnetic recording medium can be prevented.

As shown in FIG. 8, the plastic bobbin 21 is mounted on the head core 7 and the coil 20A
The number of parts and the number of bobbin mounting steps are reduced as compared with those that prevent the winding from being lost, and the cost of the apparatus can be reduced.By not mounting the bobbin, a predetermined amount of coil arrangement space is secured. , A coil having a desired number of turns can be arranged.

Second body 4 forming first flange 25
B is made of ceramics and has rigidity.
Even if the thickness of No. 5 is reduced (that is, the distance S is shortened), the first
The flange portion 25 can reliably prevent the coil 20A from protruding toward the air bearing surface 13, and can reduce the thickness of the first flange portion 20A. And
By reducing the thickness of the first flange portion 20A, the coil 20A approaches the magnetic gap 18 by that much, the amount of leakage magnetic flux of the head core 7 decreases, and the magnetic efficiency can be improved, and the density can be increased. It can be applied to a magnetic disk device that has been used.

As described above, it can be confirmed by performing the following verification that the magnetic efficiency is improved by reducing the thickness of the first flange portion 20A (ie, shortening the distance S). Was. 3, the integral equation changing the distance S from the air bearing surface 13 to the coil, the medium longitudinal component H _X of the maximum recording magnetic field intensity at a point away 0.1μm from the magnetic field intensity at that time, as a three-dimensional static magnetic field The data obtained (hereinafter referred to as the maximum recording magnetic field intensity H)
_{Called X.} ) Is plotted.

For example, when the distance S from the air bearing surface 13 to the coil is 0.19 mm, the maximum recording magnetic field intensity H _X is 6.7 KOe, and when the distance S is reduced to 0.1 mm, the maximum recording magnetic field intensity H _X It was confirmed that _X was increased to 7.3 KOe and the recording efficiency was improved. At the time of reading (reproducing), the signal from the magnetic recording medium can be picked up at a closer position, so that the reproducing efficiency is also improved.

In the above embodiment, the second body 4
The case where the notch 23 is formed on one end side of the edge 9 of the second body 4B so that the edge 9 of B has a substantially U-shape in a front view has been described as an example. The edge 9 of the body 4B has an inverted L-shape when viewed from the front (that is, the first flange 25
So that the second flange 26 is cut off).
A notch may be formed at one end of the edge 9 of the body 4B. Also in this case, the coil 20A is formed by the first flange 25.
Is prevented from dropping to the air bearing surface 13, the coil 20A does not come into contact with the magnetic recording medium, and the damage of the head core 7 and the destruction of data on the magnetic recording medium can be prevented.

【Example】

A method of manufacturing a floating magnetic head will be described as an embodiment of the present invention with reference to FIG. This manufacturing method
In addition to the manufacturing method presented in Japanese Patent Application No. 7-224775, a step of forming a substantially rectangular extraction hole 27 serving as the base of the notch 23 is added.

In FIG. 4, reference numerals 28 and 29 denote first and second slider bases which are the bases of the first and second bodies 4A and 4B, respectively, which are made of non-magnetic ceramic and each have a thick plate shape. , Formed in a thin plate shape. First, in step (1), a plurality of concave grooves 8 are formed in parallel on one surface side of the first slider base body 28, and mirrored with respect to one surface side of the first and second slider base bodies 29. Polishing is performed until it becomes.

In the next step (2), a glass film 30 having a working temperature of 980 ° C. is sputtered on the polished surfaces of the first and second slider base bodies 28 and 29 to form a glass film 30 having a thickness of 0.4 μm. To form

Subsequently, in step (3), the first and second slider bodies 28 and 29 are butted together, and 5 gf / m
A heat treatment is applied at 980 ° C. in the air by applying a force of at least m ² and bonding is performed. In this embodiment, the working temperature is 980.
The glass of ° C. was used, but this is because reliability was taken into consideration and is not limited to this. In this embodiment,
The method of joining via glass was taken as an example, but not limited to this.
For example, the first and second slider base bodies 28 and 29 may be abutted, thermocompression-bonded at a temperature near each softening temperature, and joined by material joining.

Next, in step (4), a portion facing each groove 8 in the first slider base 28 is formed along the groove 8 by laser processing (YAG laser: wavelength 266 nm). A plurality of pairs of first and second holes 10 and 11 and a substantially rectangular extraction hole 27 serving as a base of the notch 23 are formed at predetermined intervals. The first and second holes 10, 11
1 form the trailing-side and leading-side through-holes 10 and 11 in FIGS. 1 and 2, and are hereinafter referred to as the trailing-side and leading-side through-holes 10 and 11.

In this embodiment, the case where the trailing-side, leading-side through-holes 10 and 11 and the extraction hole 27 are formed by laser processing is described as an example. However, the present invention is not limited to this, and is formed by an ultrasonic cutter or ion etching. You may make it.

Subsequently, in a step (5), the first and second slider base bodies 28 are cut so as to include the through holes 10 and 11 on the trailing side and the leading side and cut out the extraction hole 27 (substantially in contact with the end face). , 29 in the direction (X, Y) intersecting the joining surface, and then performing thickness processing to form a plurality of sliders 4 composed of first and second bodies 4A and 4B equivalent to those shown in FIG. (Step (6)). Next, polishing is performed on the side surface portion 4a of the second body 4B (on the side where the head core 7 is joined) until a mirror surface is obtained.
The joint of the head core 7 will be dealt with.

Thereafter, the joining of the head core 7 and the coil 2
The floating magnetic head 1 is obtained by winding 0A and 20B.

[0030]

According to the present invention, since the rail-side flange formed at the edge of the second body suppresses the deformation of the coil to the rail side and prevents the coil from rolling, the coil falls off to the rail side. This prevents the coil from coming into contact with the magnetic recording medium even if the slider's flying height on the magnetic recording medium is small, thus preventing damage to the head core and destruction of data on the magnetic recording medium. it can.

In addition, the number of components and the number of bobbin mounting steps are reduced as compared with a floating type magnetic head in which a plastic bobbin is mounted on a head core to prevent winding of a coil, thereby reducing the cost of the apparatus. By not mounting the bobbin, a predetermined amount of coil arrangement space is secured, and a coil having a desired number of turns can be arranged.

Since the second body is made of ceramics and has rigidity, even if the thickness of the rail-side flange formed at the second edge portion is reduced, the rail-side flange has a coil formed on the rail-side. And the thickness of the flange on the rail side can be reduced. And by reducing the thickness of the flange on the rail side,
As the coil approaches the magnetic gap, the amount of magnetic flux leakage from the head core is reduced, so that the magnetic efficiency can be improved, and the application to a high-density magnetic disk device becomes possible.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a floating magnetic head according to an embodiment of the present invention.

FIG. 2 is a partial sectional view of FIG.

FIG. 3 is a characteristic diagram showing a relationship between a distance from an air bearing surface to a winding of the floating type magnetic head and a maximum recording magnetic field.

FIG. 4 is a view showing a manufacturing process of the floating magnetic head.

FIG. 5 is a perspective view showing an example of a conventional floating magnetic head.

FIG. 6 is a sectional view showing a state where a coil is provided in the floating magnetic head.

FIG. 7 is a cross-sectional view showing a state in which the coil is unwound.

FIG. 8 is a cross-sectional view showing a state where a plastic bobbin is mounted on a head core of the floating type magnetic head.

[Description of Signs] 1 Floating magnetic head 2, 3 First, second rail 4 Slider 4A, 4B First, second body 7 Head core 8 Concave groove 9 Edge 10, 11 Trailing side, leading side transparent Holes 20A, 20B Coil 23 Notch 25, 26 First and second flanges

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 5/60 G11B 5/127 G11B 5/17

Claims (2)

(57) [Claims] 1. A floating magnetic head in which a recording / reproducing head core is joined to a side surface on one end side of a slider having a rail for generating a levitation force on a magnetic recording medium, wherein the slider is joined to each other. A first body and a second body, wherein a groove is formed on a joint surface side of the first body with the second body, and a leg of the head core is formed on a second body to which the head core is joined. The second body is formed such that a coil hole for accommodating the coil is formed together with the groove except for a plate-shaped edge portion to which the second body is joined, and the edge portion of the second body is substantially U-shaped when viewed from the front. A notch is formed at one end of the edge of the floating magnetic head. 2. The floating magnetic head according to claim 1, wherein the edge of the second body is viewed from the front instead of the notch formed so that the edge of the second body is substantially U-shaped when viewed from the front. A floating magnetic head, wherein a notch is formed at one end of an edge of the second body so as to form an inverted L-shape.