JP2872384B2 - Magnetic head slider and magnetic disk device - Google Patents

Description

The present invention relates to a magnetic head slider, such as a magnetic disk device, that floats on a surface of a recording medium on which it travels to a minute floating clearance, and particularly has a good flying characteristic. Related art magnetic head slider suitable for mass production [Prior art] A conventional magnetic head slider for a magnetic disk device is, as described in JP-B-57-569, a flat portion and a gas portion on both sides of the slider. So-called tapered flat type sliders having a straight gas bearing rail with an inflow side slope are used. A bleed portion cut between the two gas bearing rails to a sufficient depth that does not cause a gas bearing effect is formed. The actual depth of the bleed portion is about 100 μm at the boundary with the gas bearing.

To increase the recording capacity of the magnetic disk device, it is necessary to reduce the clearance between the magnetic head slider and the recording medium. As the flying height becomes narrower, the air film stiffness is increased to minimize the flying height fluctuation, and the change in the flying height in response to the change in the peripheral speed is reduced by applying positive pressure to the flying surface of the slider. There has been proposed a negative pressure utilizing slider in which a negative pressure generating portion is provided in addition to the generating portion, and a negative pressure suction force acts as a pressing load. However, in this type of slider, as the angle between the rotational direction (tangential direction) of the disk and the longitudinal direction of the slider (hereinafter referred to as the yaw angle) increases, the inflow of gas from the side surface of the slider increases, and the correctness of the gas bearing rail increases. There is a disadvantage that the pressure generating force is reduced and the flying height is reduced. As a countermeasure, as described in JP-A-62-110680,
On both gas bearing rails of the negative pressure type slider, a step of a groove-shaped concave portion is provided in a direction orthogonal to the rail longitudinal direction, and the bearing surface on the gas bearing rail is divided into two front and rear sides, and there is a yaw angle. Even in such a case, a method for preventing a decrease in the positive pressure behind the rail has been proposed (FIG. 20). Also, as another measure,
As described in JP 63-21271 and U.S. Pat.No. 4,673,996, a conventional tapered flat type or
A method has been proposed in which a slider utilizing a negative pressure is provided with an inclined portion or a stepped portion on both edges of both gas bearing rails so as to provide a bearing effect for a gas flow flowing from the side surface of the slider (FIG. 22).

[Problems to be solved by the invention]

The prior art described above has a problem because the following points are not considered.

First, as described in Japanese Patent Application Laid-Open No. Sho 62-110680, in the method of providing a groove on the gas bearing rail of a negative pressure utilizing slider, as shown in FIG. In some cases, the pressure decrease is small at the rear end of the inclined part that has a bearing effect and at the step at the rear end of the groove on the rail, but the pressure behind the bearing surface decreases due to the inflow of gas flow from the slider side surface, and it rises. There was a problem that the amount could not be reduced.

Further, at the time of contact start stop, the area which slides on the disk surface becomes large due to the existence of the cross rail, and there is a problem in terms of sliding resistance.

Further, as shown in FIG. 21 (b), the inflow of the gas flow from the side surface of the slider disturbs the balance of the moment around the center of gravity of the slider in the lateral direction of the slider, and the slider tilts around the central axis in the longitudinal direction. (The angle is called the roll angle.)

Secondly, as shown in FIGS. 22 (a) and 22 (b), an inclined surface or a stepped portion having a bearing effect against the inflow of the gas flow from the side surface of the slider is provided on both edges of the pair of gas bearing rails. ) Provided in the slider (US Pat. No. 4,673,996) has a long bearing surface at both edges of the rail, and as shown by the dashed line in the graph of FIG. There was a problem that the change in the positive pressure was large and the flying height was not constant.

In addition, as shown in FIG. 22 (b), when the inclined surfaces (or step portions) are provided at both edges of the gas bearing rail, and the lower cross rails are combined together, the processing process becomes complicated, There is a problem that the cost increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic head slider which has a small change in flying height with respect to a change in yaw angle and peripheral speed and can be manufactured with good mass productivity.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a pair of gas bearing rails, which lifts the slider by a positive pressure generated by the recording medium of a slider disposed opposite to a rotating recording medium; In a magnetic head slider in which a bleed portion depressed from the gas bearing rail surface is formed between gas bearing rails, the bleed portion has a depression reaching an outflow end of the gas flow, and bearings are provided at both ends of the gas bearing rail. A step portion having an effect and a separation groove for separating the gas bearing rail into a plurality of parts in the longitudinal direction of the slider are provided, and the depth of the step portion and the separation groove is the same as the bleed portion. And

The gas bearing rail may have a stepped portion on both edges, a separation groove for dividing the gas bearing rail into a plurality of pieces in the longitudinal direction of the slider, and a dent or curve of the bleed portion. Both edges of the bearing rail and an edge of the separation groove may be formed as inclined surfaces.

[Action]

According to the above configuration, the bleed portion formed between the pair of gas bearing rails of the slider and depressed from the gas bearing rail surface reaches the outflow end (the bleed portion is a first depression and corresponds to a second depression). By providing, the gas flowing into the bleed portion after the pressure rises in the first depression,
The second depression spreads and becomes a flow to generate a negative pressure. Usually, the negative pressure generating force by the second depression can be larger than the pressure generating force by the first depression. Also, since the bleed portion is recessed from the gas bearing rail, the sliding area with the disk surface does not increase.

Also, by providing a step at both edges on the gas bearing rail and a separation groove for dividing the gas bearing rail into front and rear, more than one pair of planes having a bearing effect on the front and both sides can be formed on the gas bearing rail. The positive pressure for floating the floating head slider from the recording medium is mainly due to the compression of the gas flow flowing from the entire surface of the bearing rail. Therefore, if the conventional head slider has a yaw angle, as shown in FIG. Accordingly, the gas flow flowing from the bearing rail side surface increases, and the positive pressure generating force decreases.

In addition, as shown in FIG. 3, simply providing the inclined surfaces (or steps) having a bearing effect on the side surfaces of the bearing rails on both sides of the slider causes a change in the yaw angle and a change in the approach distance of the gas flow on the side surfaces of the bearing rails. The amount of change in the pressure generating force increases, and the flying height cannot be kept constant. According to the present invention, the bearing surface on the bearing rail is divided into a plurality of parts in the longitudinal direction to reduce the length of each bearing surface, and further, by providing a step (or inclination) also on the side surface of the bearing surface, As shown in Fig. 4, after reducing the gas flow flowing from both sides of the bearing due to the change in the yaw angle, the bearing effect is also exerted on the gas flow flowing from the side of the bearing surface to reduce the change in the flying height. Can be minimized.

Further, by making the step and the groove between the bleed portion and the gas bearing surface the same height, these can be formed by one etching process, and the processing cost can be kept low.

〔Example〕

Hereinafter, some embodiments of the present invention will be specifically described with reference to the drawings.

In FIG. 1, a slider 1 has an inclined portion 2 at a front portion. Then, on both sides of the slider 1, following the inclined portion 2, the first flat portion 4, the separating groove 6, the second flat portion 5, and the step portions on both sides of the first flat portion and the second flat portion 5. 7 is provided at a depth of D1. A bleed portion 3 is provided between the pair of gas bearing rails following the inclined portion, and a dent 8 reaching the outflow end of the gas flow is provided in the bleed portion 3 at a depth D2. The step portion 7, the separation portion 6, and the bleed 3 are formed on the same plane, and can be machined with high precision by performing an etching process such as sputtering.

Usually, the magnetic disk device reads and writes information at an arbitrary radial position on the disk, so that the magnetic head slider can be moved in the disk radial direction. In the rotary actuator type magnetic disk device, the flowing direction and the flowing speed of gas into the slider change depending on the radial position on the disk on which the slider is placed, and the pressure distribution on the gas bearing surface changes, so that the slider flies. The amount changes. According to the present embodiment, the change in the flying height can be suppressed as much as possible. First, with respect to a change in the inflow speed of the gas flow, the inclined portion 2 serving as a positive pressure bearing and the following first flat portion 4,
The increase and decrease of the positive pressure of the separation portion 6 and the subsequent second flat portion 5 and the increase and decrease of the negative pressure generated by the gas flow that has flowed into the bleed portion 3 being spread by the depression 8 to maintain a balance are maintained. Changes can be suppressed.

Next, a change in pressure with respect to the yaw angle will be described with reference to FIGS. 5 and 6 (a) and (b). Fig. 6 (a) (b)
Shows the difference in the pressure distribution depending on the presence or absence of the yaw angle on the cross section taken along lines AA and BB in FIG. 5, respectively. The solid line represents the case where the yaw angle is present, and the broken line represents the case where the yaw angle is not present. Since the first and second flat portions 4 and 5 have inclined portions or stepped bearing portions on both sides and a front portion, they also have a bearing effect against a gas flow flowing from the side surface when there is a yaw angle. The change in the pressure of the gas bearing due to the change in the yaw angle is remarkable toward the rear of the bearing. In this embodiment, however, the separating surface 6 divides the bearing surface into a plurality of parts, and the length of each bearing surface , The pressure change can be suppressed.

According to the present embodiment, the change in the flying height with respect to the yaw
Shown in the figure. The solid line shows the change in the flying height of the outflow end of the bearing rail on the leeward side of the gas flow flowing into the slider side surface when there is a yaw angle, and the dashed line shows the change in the floating amount of the outflow end of the bearing rail on the leeward side of the gas flow. Represents The dashed line is U.S. Pat.No. 4,673,996
This is due to the shape shown in FIG.

Further, in the present embodiment, the bleed portion 3, the separation portion 6, and the step portion 7 are on the same plane, so that the turbulence of the gas flow is reduced and the adhesion of dust is less likely to occur. Further, in the conventional negative pressure generating type slider, as shown in FIG. 20, the cross rail 18 is formed in the same plane as the flat portions 4 and 5, and the sliding area with the medium surface at the time of contact start stop is reduced. Although there is a problem in terms of increase and wear, in the present invention, since there is no cross race, the sliding area is not increased, and the possibility of contact with the projection on the medium surface during flying is suppressed. Thus, damage to the medium surface and crash can be avoided.

8 and 9 show a second embodiment of the present invention.
In this embodiment, the inclined portion 2 in FIG. 1 is eliminated, and the front part in the plan view 4 in FIG. 1 is also a positive pressure bearing due to a step.
In the present embodiment, the slider shape can be formed with high precision by performing two etching processes such as sputtering, without using mechanical processing.

FIG. 10 and FIG. 11 show a third embodiment of the present invention.
Etching such as spattering can easily process steps having an arbitrary curve.
Is also arbitrary. This embodiment eliminates anisotropy in the gas inflow direction by making the front edge of the second flat portion 5 and the front of the depression 8 arc-shaped, so that even if the gas inflow direction changes due to the yaw angle, the front edge The change in the pressure of the section can be reduced.

Further, by making the dent 8 narrow on the inflow side, even when there is a yaw angle, the gas flowing into the flat portions 4 and 5 does not pass through the dent 8 before that, and therefore the gas flow is not disturbed and the flat portion is not disturbed. It can flow into 4,5, and a stable positive pressure can be obtained.

12 and 13 show a fourth embodiment of the present invention.
In this embodiment, the gas bearing plane is divided into three in the longitudinal direction of the slider. By shortening the length of each plane, even if there is a yaw angle, the proportion of the gas flow flowing from the front of the plane among the gas flow passing on the bearing plane is increased, , The change in the flying height can be suppressed.

14 and 15 show a fifth embodiment of the present invention.
In this embodiment, the gas bearing plane is divided into three in the longitudinal direction of the slider, and each plane is formed into an ellipse or a circle to reduce anisotropy. The pressure does not change. Furthermore, the slider can be formed by two etching processes such as spattering by eliminating the inclined portion on the front surface of the slider, and with high accuracy,
The shape is excellent for mass production.

FIG. 16 and FIG. 17 show a sixth embodiment of the present invention.
The front part and both sides of each gas bearing plane are formed by inclined parts to make it difficult for dust to adhere.

FIG. 18 is a plan sectional view of a linear rotary disk storage device to which the head slider according to the present invention is attached. The guide arm 14 is connected to the carriage 13, the transducer support device 15 of the guide arm 14 is connected, and the flying head slider 1 is mounted on the tip of the transducer support device 15. The slider 1 is driven by a boil coil motor 16 to advance and retreat in the radial direction of the rotating disk storage medium 17. Since the flying height of the slider is small and stable with respect to the yaw angle change according to the present embodiment, the flying height of the slider can be reduced, and high-density storage of a storage medium can be realized.

FIG. 19 shows another embodiment of the present invention, and is a partially crushed perspective view of an in-line type rotary disk storage device to which the floating head slider 1 of the present invention is mounted, wherein a transducer connected to a carriage 13 is shown. The floating head slide 1 mounted on the tip of the support device 15 is shown. According to this embodiment, a similar effect was obtained.

〔The invention's effect〕

According to the present invention, by providing a plurality of depressions for generating a negative pressure and a plurality of positive pressure generation surfaces having a gas bearing effect on both side surfaces and a front portion in the longitudinal direction on both sides of the slider, the speed of the inflowing gas and the inflow of the inflow gas are improved. Approximately the same flying height can be obtained regardless of the direction,
So-called zone bit recording, in which the magnetic recording linear density in the tangential direction is constant anywhere on the recording medium, can be realized, and a high recording density of the recording medium can be achieved.

In addition, it is possible to form the slider by non-mechanical processing, thereby improving the processing accuracy.

[Brief description of the drawings]

1 and 5 are perspective views of one embodiment of the present invention, FIGS. 2, 3, and 4 are explanatory views of the effects of the conventional example and the present invention, and FIG. FIG. 5 is an explanatory diagram showing the relationship between the yaw angle and the flying height of the pressure distribution in the AA and BB cross sections in FIG.
FIG. 7 is a diagram showing a change in the flying height with respect to the yaw angle, FIGS. 8 to 17 are side and front views of the second to sixth embodiments according to the present invention, and FIGS. FIG. 20 is a plan view and a perspective view of an application example of the present invention, FIG. 20 is a perspective view of a conventional example, and FIG. 21 is a diagram showing a difference between the presence and absence of a pressure distribution yaw angle in the AA and BB cross sections in FIG. FIG. 22 is a perspective view showing another conventional example. 1 ... Slider, 2 ... Incline, 3 ... Bleed, 4
... A first flat portion, 5... A second flat portion, 6... A separation groove, 7... A step portion, 8.
Gas flow, 11 third plane part, 12 rail side inclined part, 13 carriage, 14 guide arm, 15 transducer support device, 16 voice coil motor,
17 Disk storage medium. 18: Cross rail, D1: Depth of step, D2: Depth of negative pressure generating part.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mikio Tokuyama 502, Kandachicho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. (56) References JP-A-3-2055671 (JP, A) JP-A-3-3 132981 (JP, A) JP-A-3-63978 (JP, A) JP-A-63-255883 (JP, A) JP-A-62-110680 (JP, A) JP-A-60-211671 (JP, A) Hira 3-89569 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) G11B 21/21 101 G11B 5/60

Claims (3)

(57) [Claims] 1. A slider arranged to face a rotating recording medium, and the slider is caused to fly by a positive pressure generated by a gas flow accompanying rotation of the recording medium on a surface facing the recording medium. In a magnetic head slider in which a pair of gas bearing rails and a bleed portion depressed from the gas bearing rail surface are formed between the gas bearing rails, the bleed portion has a depression reaching an outflow end of the gas flow, A step having a bearing effect at both ends of the gas bearing rail, and a groove for dividing the gas bearing rail into front and rear portions are provided, and a step at both edges of the gas bearing rail and the bottom of the groove are the same as the bleed portion. A magnetic head slider having a height. 2. A slider disposed on a surface of a slider opposed to a rotating recording medium facing the recording medium, the slider being floated by a positive pressure generated by a gas flow accompanying the rotation of the recording medium. A plurality of protrusions having a bearing effect around the slider are disposed on both sides of the slider in the longitudinal direction, and a recess reaching the outflow end of the gas flow is provided between the protrusions. Head slider. 3. A magnetic disk device on which the magnetic head slider according to claim 1 is mounted.