JPH0863925A - Floating head slider and manufacture thereof - Google Patents

Abstract

PURPOSE: To inexpensively provide a floating head slider suited to a rotary type positioner and having excellent uniformity in floating quantity. CONSTITUTION: Two side rails 15 and 16 having tapered parts as air flowing in ends are provided in both ends paralelly in a longitudinal direction and in a width direction and a center rail 14 is provided in the air flowing out end of the center part. The full length of the center rail 14 (center rail length L12 ) is set to 80% of the full length of the floating type head slider (floating type head slider length L11 ) 11 and the full lengths of the side rails 15 and 16 (side rail length L13 ) 13 are set to 70% of the floating type head slider L11 . Thus, by setting the full length of each rail shorter than the full length of the floating type head slider, the compression length of an air flow is reduced and a low floating quantity is realized under a low load condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floating head slider used in a magnetic disk device and a method for manufacturing the same, and more particularly to a floating head slider mounted on a rotary positioner.

[0002]

2. Description of the Related Art Conventionally, as a magnetic head for reading and writing information in a magnetic disk device, there is a two-rail type floating head slider as shown in FIG. Here, FIG.
(A) is a front view, (b) and (c) are a side view and a bottom view, respectively. This two-rail type floating head slider has a taper 73 at the air inflow end (upper end in the figure).
And has two rails 71 and 72 that are parallel to the length direction and are provided at both ends in the width direction. Then, the positive pressure generated on the rail surface and the load applied via a suspension (not shown) are balanced to obtain a predetermined flying height.

The characteristics of this floating head slider are high air film rigidity, easiness of machining by a simple rail shape, easiness of flying height design and the like. However, basically, a magnetic disk medium (hereinafter referred to as a disk)
It is premised that the rail length direction is parallel to the air flow generated when the rotation occurs, and in order to support the rotary type positioner that performs the oscillating motion that is currently the mainstream, the load point Situation in which design must proceed in consideration of the amount of offset to the center of gravity of the floating head slider and the layout on the disk of the angle (yaw angle) between the longitudinal direction of the floating head slider and the tangential direction of the track on the disk. It is in.

Further, as a floating head slider which has a high flying stability under a low load and can easily realize a low flying height, FIG.
There is a negative pressure type floating head slider as shown in FIG. Here, FIG. 8A is a front view, FIG. 8B is a side view, and FIG. 8C is a bottom view.

This negative pressure type floating head slider is provided with two rails 81 and 82 and a cross rail 83, generates a negative pressure in a recess 84 surrounded by each rail, and the negative pressure and the positive pressure generated on the rail surface. It is configured to balance the pressure and the load applied via a suspension (not shown) to obtain a predetermined flying height.

However, in the negative pressure type floating head slider,
There is a problem that deposits such as dust are likely to be deposited on the front and rear steps (steps) of the cross rail 83, which reduces the flying height, which is one of the factors that cause a head crash accident. Further, as in the case of the two-rail type floating head slider described above, the yaw angle greatly depends on the flying posture, and when mounted on a rotary positioner, it is difficult to secure effective flying stability. There is a situation.

[0007]

With the recent trend toward miniaturization, high-speed access (positioning), and high recording density of magnetic disk devices, the floating head slider has a small size, a light weight, and a light load. It is required to uniformly realize a low flying height of 1 μm or less on the disk, and it is important to design the rail surface shape that generates a pressure distribution that has high air film rigidity and improves the followability to the disk. Is becoming. Further, as described above, the recent magnetic head positioning mechanism (positioner) has changed from the former linear positioner that performs linear motion to the rotary positioner that is advantageous for high-speed access. The pressure generated on the bearing surface also greatly changes depending on the position on the disk, the pressure balance is lost, and the roll angle, pitch angle, and flying height of the floating head slider fluctuate.

For this reason, it is necessary to ensure the floating stability of the floating head slider in consideration of the air flow velocity increasing toward the outer circumference of the disk, the setting of the yaw angle, the load position applied to the floating head slider, and the like. Particularly, from the viewpoint of high-speed access, when the load point serving as a support point of the floating head slider is deviated from the slider center of gravity, there is a problem that the stability of the slider is impaired due to a sudden increase or decrease in acceleration.

In many current magnetic disk devices, a start / stop system called a CSS (contact start / stop) system in which the rail surface of the floating head slider slides in contact with the disk is used. To reduce damage to the magnetic head and disk surface due to intermittent contact sliding of the floating head slider and disk when stopped, establish a boundary head lubrication condition for a short time and reduce the damage probability I have to do it.

Further, in the case of a two-rail slider, if the slider is downsized, a sufficient flying height at the air inflow end cannot be obtained, so that the average flying height of the entire slider decreases,
There is concern about an increase in contact probability with the medium and a decrease in CSS durability.

As means for solving the above problems,
Recently, a floating head slider having a complicated rail surface shape and a complicated recess shape has been developed (for example,
JP-A-2-101688, JP-A-4-35676
No. 5). The rail shape of these floating head sliders is difficult to form by ordinary machining, and is formed by a wet method using a mask or a dry etching method according to the machining process, but there is a drawback that the manufacturing cost becomes high.

An object of the present invention is to solve these problems and to make a flying head slider, which has a uniform flying height on a disk compatible with a rotary type positioner, and has excellent flying stability and CSS resistance, at a low price. To provide.

[0013]

According to a first aspect of the present invention, there is provided a first rail extending in the longitudinal direction and arranged at a central portion for obtaining a levitation force by a fluid bearing action on a disc, and both ends of the first rail. In a floating head slider with second and third rails arranged, the length of the first rail is 80% of the total length of the floating head slider from the air outflow end.
The lengths of the second and third rails are 50 to 50 times the total length of the floating head slider from the air inflow end.
It is 80%, and the rail widths of the second and third rails are configured to decrease at a rate of change of at least two steps from the air inflow end toward the air outflow end.

The second invention is based on the second and third aspects.
The length of the rail is L ₁ , the position where the rail width changes stepwise from the air inflow end is L ₂ , the rail width at the air inflow end is W ₁ , and the rail width at L ₂ is W ₂ Where L ₁ , L ₂ and W ₁ , W _{2 have} a ratio of L ₂ : L ₁ = 1: 2.2 to 2.5 W ₂ : W ₁ = 1: 1.2 to 1. 6 and the rail width of the first rail changes in two steps from the air inflow end side toward the air outflow end side, and the rail width of the first step is the second from the air inflow end side.
And the third rail increases at an angle equal to the decrease angle of the first rail, the width of the second rail becomes parallel to the longitudinal direction of the floating head slider, and the length of the parallel portion is the first rail. Is 30% or more of the length.

In a third invention, the rail width of the first rail changes in at least two steps from the air inflow end side toward the air outflow end side, and the rail width of the first step is the air inflow end. 70% or more of its total length is parallel to the slider longitudinal direction, the rail width of the second stage monotonically increases toward the air outflow end side, and the widths of the second and third rails are It is characterized in that it is bilaterally symmetric, and the rail widths thereof change in at least two steps, and monotonically decreases from the air inflow end toward the air outflow end.

A fourth invention is a method of manufacturing the floating head slider according to the second invention, characterized by including a step of processing the rail of the floating head slider with only one kind of grinding blade (blade). .

[0017]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view showing an example of a rail surface shape of a floating head slider according to the first invention. Further, FIG. 3A is a diagram for explaining the relationship between the flying position of the floating head slider on the disk and the flying height at that time, and FIGS. 3B and 3C respectively show the floating head slider. It is a figure which shows the floating posture in a pitch direction and a roll direction.

In this embodiment, as shown in FIG. 1, two side rails 15 which are parallel to the lengthwise direction and have a taper at both ends in the widthwise direction as air inflow ends (upper ends in the figure), 1
6 and a center rail 14 at the air outflow end (lower end in the figure) at the center. And the center rail 1
The total length (center rail length L ₁₂ ) 12 of 4 is 80 of the total length (floating head slider length L ₁₁ ) 11 of the floating head slider.
%, The total length (side rail length L ₁₃ ) 13 of the side rails 15 and 16 is equal to the floating head slider length L ₁₁ (1
It is set to 70% of 1). In this way, by setting the total length of each rail shorter than the total length of the floating head slider, it is possible to reduce the compressed length of the air flow and to achieve a low flying height under low load conditions.
By making the side rail width variable, it is possible to improve the flying height uniformity in response to yaw angle fluctuations that occur when the side rail is mounted on a rotary positioner.

When the center rail length L ₁₂ (12) is 80% or less of the floating head slider length L ₁₁ (11), the center rail 14 is mounted in order to mount the magnetic head on the side surface of the air outflow end. When the required width of the air outflow end is secured, it is necessary to increase the center rail inclination angle θ ₁ and shorten the width of the air inflow end in order to realize a low flying height. As a result, since the air compression length does not change so much with respect to the fluctuation of the yaw angle of the floating head slider, the flying height fluctuation characteristic is, for example, the characteristic curve (solid line) of FIG.
As shown by 31, the flying height increases from the inner circumference to the middle circumference of the disk, and the flying uniformity deteriorates.

When the side rail length L ₁₃ (13) is 50% or less of the floating head slider length L ₁₁ (11), the pitch of the floating head slider is as shown in FIGS. 3 (b) and 3 (c). Since the air film rigidity with respect to the movement in the roll direction and the roll direction cannot be sufficiently obtained, the followability to the disk is significantly deteriorated. Furthermore, the side rail length L
₁₃ (13) is 80 of the floating head slider length L ₁₁ (11)
%, The air film rigidity of the slider in the roll direction is smaller than that of the conventional two-rail type floating head slider as shown in FIG. 7, so that the effect of speed and acceleration applied during seek operation causes It greatly tilts in the roll direction, increasing the risk of contact with the disc.

FIG. 2 is a schematic view showing an example of the rail surface shape of the floating head slider according to the second invention.

In this embodiment, as shown in FIG. 2, the basic shape is the same as that of the floating head slider of the first invention, and air is introduced into both ends in the width direction parallel to the length direction. Two side rails 19 and 20 having a taper at the ends (upper end in the drawing) and a center rail 18 are provided at the center.

Regarding the dimensions of each rail, the position where the total length (side rail length L ₂₁ ) 21 of the side rails 19 and 20 and the width of the side rails 19 and 20 change stepwise is the first step of the side rails. The length (first side rail length L ₂₂ ) 22 and the width of the side rails 19, 20 on the air inflow end side are (side rail width W ₂₁ ) 25, first side rail length L ₂₂ (22) The width of the side rails 19 and 20 in the above is defined as the width of the first step of the side rail (side rail first step width W ₂₂ ).

Next, the ratio of L ₂₂ : L ₂₁ is 1: 2.2-2.
5 and the ratio of W ₂₂ : W ₂₁ is 1: 1.2 to
The width of the center rail 18 is changed in two steps from the air inflow end toward the air outflow end while the first step is set to the side rail 19,
The angle is increased at an angle equal to the inclination angle of the first stage of 20. That is, both the center rail inclination angle 27 and the side rail inclination angle are set to “θ ₂ ”. And the center rail 18
The air outflow end side of is parallel to the longitudinal direction of the floating head slider and is the length of the parallel portion of the parallel portion (center rail linear portion length L ₂₃ ) 23.
Is set to 30% or more of the total length (floating head slider length L ₂₄ ) 24 of the floating head slider.

In the thus constructed floating head slider, the ratio of L ₂₁ , L _{22 and} the ratio of W ₂₁ , W ₂₂ are closely related to the pitch angle 34 and roll angle 35 of the floating head slider shown in FIG. Where the ratio of L ₂₂ : L ₂₁ is fixed in the range of 1: 2.2 to 2.5, and W ₂₂ : W _21.
When the ratio of is increased over the range of 1: 1.2 to 1.6,
In the steady floating state, the pitch angle becomes excessively large, and the air film rigidity in the pitch direction decreases. As a result, the flying stability during seek operation is impaired, and the ability to follow the disk during steady flying also deteriorates.

When the ratios of L ₂₂ : L ₂₁ and W ₂₂ : W ₂₁ are decreased below the above range, the roll angle increases in the steady floating state, so that the inner circumferential side of the disk is moved during seek operation. The levitation dynamic characteristics differ between when seeking and when seeking to the outer peripheral side, making it difficult to design stably for a levitation posture. Further, the possibility of contacting the disk near the air outflow end of the side rail having a relatively low air film rigidity increases.

Next, W_{twenty two}: W_{twenty one}The ratio of 1: 1.2-1.
Fixed to the range of 6 and L_{twenty two}: L_{twenty one} The ratio of 1: 2.2
Increasing above the range of 2.5 effectively results in sideray
Since the width of the roll becomes narrower, the air film rigidity in the roll direction is low.
This leads to a decrease in the pitch angle in the lower position and during normal ascent.

The decrease in air film rigidity in the roll direction significantly impairs the floating stability during seek operation, and the decrease in pitch angle increases the sliding time of the disk when the apparatus is stopped and started.
CSS (contact start stop) may deteriorate durability. In addition, W _22: the ratio of W ₂₁ 1:
When it is decreased from the range of 1.2 to 1.6, the side rail is effectively close to a rectangle, so that the roll angle is increased in the steady floating state.

Here, the characteristic curve (chain line) 32 in FIG.
L ₂₁ , L ₂₂ , W ₂₁ , and W ₂₂ are optimized, and the center rail linear portion length L ₂₃ (23) is changed to the floating head slider length L ₂₄ (2
4) shows the fluctuation characteristics of the flying height when it is 40%, and FIG.
The curve 33 (dashed-dotted line) indicates the flying height variation characteristic when the center rail straight line portion length L ₂₃ (23) is 20% of the floating head slider length L ₂₄ (24). When the center rail linear portion length L ₂₃ (23) is optimized, as shown by the characteristic curve (solid line) 31 in FIG.
When the flying height variation characteristic having a maximum value is exhibited in the middle circumference of the disk and the center rail straight line partial length L ₂₃ (23) is shortened, as shown by a characteristic curve (dashed line) 33 in FIG. The flying height increases toward the side, and it becomes impossible to obtain the flying uniformity.

FIG. 4 is a schematic view showing an example of the rail surface shape of the floating head slider according to the third invention.
FIG. 6 is a diagram showing the relationship between the flying position of the floating head slider of FIG. 4 on the disk and the flying height at that time.

In this embodiment, as shown in FIG. 4, the basic shape is similar to that of the floating head slider of the first invention, and the side rails 44 and 45 are bilaterally symmetrical. When mounted on a rotary type positioner, it is possible to reduce the roll angle fluctuation of the floating head slider. Also, by changing each rail width in two steps, it becomes possible to adjust the flying height and pitch angle of the floating head slider.

Here, the characteristic curve (solid line) 51 of FIG.
The flying height variation characteristic is shown when the length of the straight part of the center rail 43 (center rail straight part length L ₃₂ ) 42 is 70% of the total length of the floating head slider (floating head slider length L ₃₁ ) 41. Further, the characteristic curve (chain line) 52 in FIG. 5 is the straight part length L ₃₂ (42) of the center rail.
The flying height variation characteristic is shown when is 50% of the floating head slider length L ₃₁ (41).

In this case, the length of the straight part of the center rail 43 is extended to increase the sensitivity of the flying head slider flying height fluctuation to the yaw angle, thereby reducing the flying height at the outer circumference of the disk having a high circumferential speed and thus achieving the flying uniformity. It becomes possible to obtain. In addition, the straight length of the center rail L ₃₂ (4
When 2) is shortened, the characteristic becomes as shown by the characteristic curve 52 in FIG. 5, and the flying height variation increases.

Next, a method of manufacturing the floating head slider of the present invention will be described.

FIG. 6 is a view showing an example of rail machining of a floating head slider according to claim 4 of the present invention.
The rail processing of the floating head slider is performed by a grinding method. When the rail processing of the floating head slider shown in FIG. 2 is performed by using a grinding blade (blade), the rail surface thereof is as shown in FIG. The processing width 61 (area surrounded by solid lines a and a ′), the processing width 62 (area surrounded by chain lines b and b ′), and the processing width 63 (area surrounded by alternate long and short dash lines c and c ′) are deepened. It is achieved by grinding to about 40 μm. In this case, the order of grinding may be arbitrary, and the width of the grinding blade used may be determined by the minimum width of each part.

Further, as shown in FIG. 2, the center rail inclination angle 27 and the side rail first stage side rail inclination angle 2 are shown.
8 and the same angle (θ _{2 in the} figure) are set, the angle of the floating head slider (grinding direction) only needs to be changed three times during grinding, and one type of grinding blade It can be processed with a (blade).

The flying characteristics described above correspond to the case where the yaw angle is small on the inner peripheral side of the disk and is large on the outer peripheral side of the disk in any of the embodiments.

[0039]

As described above, according to the present invention, by forming the rail shape of the floating head slider to have a predetermined size, the floating head slider which corresponds to a rotary type positioner and is excellent in flying height uniformity can be manufactured at a low price. There is an effect that can be provided to.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a rail surface shape of a floating head slider according to a first invention.

FIG. 2 is a schematic view showing an example of a rail surface shape of a floating head slider according to a second invention.

FIG. 3 is a diagram illustrating a relationship between a flying position of a floating head slider on a disk and a flying height at that time, and a flying posture of the floating head slider.

FIG. 4 is a schematic view showing an example of a rail surface shape of a floating head slider according to a third invention.

5 is a diagram for explaining the relationship between the flying position of the floating head slider of FIG. 4 on the disk and the flying height at that time.

FIG. 6 is a schematic view showing a method of processing a floating head slider according to a fourth invention.

FIG. 7 is a schematic diagram showing a rail surface shape of a conventional two-rail type floating head slider.

FIG. 8 is a schematic view showing a rail surface shape of a conventional negative pressure type floating head slider.

[Explanation of symbols]

11 Floating Head Slider Length (L ₁₁ ) 12 Center Rail Length (L ₁₂ ) 13 Side Rail Length (L ₁₃ ) 14, 18, 43 Center Rail 15, 16, 19, 20, 20, 44, 45 Side Rail 17 Center Rail Inclination Angle (Θ ₁ ) 21 Side rail length (L ₂₁ ) 22 Side rail first step length (L ₂₂ ) 23 Center rail linear portion length (L ₂₃ ) 24 Floating head slider length (L ₂₄ ) 25 Side rail width (W ₂₁ ) 26 Side Rail First Step Width (W ₂₂ ) 27 Center Rail Inclination Angle (θ ₂ ) 28 Side Rail Inclination Angle (θ ₃ ) 31, 51 Flying Height Variation Characteristic Curve (solid line) 32, 52 Flying Height Variation Characteristic Curve (chain line ) 33 flying height variation characteristic curve (dashed line) 34 pitch 35 roll angle 41 flying head slider length (L ₃₁₎ 42 center rail straight portion length (L ₃₂₎ 61 Bed Processing width by chromatography de (a, a ') 62 blade according to the processing width (b, b') 63 blade according to the processing width (c, c ') 71,72,81,82 rails 73 taper 83 cross rail 84 recess

Claims (4)

[Claims] 1. A first rail which extends in the longitudinal direction and is arranged at a central portion, and a second rail which is arranged at both ends of the first rail, which obtains a levitation force by a fluid bearing action on a magnetic disk medium.
And a third rail, wherein the length of the first rail is 80% or more of the total length of the floating head slider from the air outflow end, and the length of the second and third rails. Is 50 to 80% of the total length of the floating head slider from the air inflow end, and the rail widths of the second and third rails are in at least two stages from the air inflow end toward the air outflow end. A floating head slider characterized by being configured to decrease at a rate of change. 2. Regarding the second and third rails, the total length thereof is L ₁ , the position where the rail width gradually changes from the air inflow end is L ₂ , and the rail width at the air inflow end is W. _1, wherein when the rail width in L ₂ and W _2, the ratio of the L _1, L ₂ and the W _1, W _{2 are, L 2: L 1 = 1} : 2.2~2.5 W 2: W ₁ = 1: 1.2 to 1.6, and the rail width of the first rail changes in two steps from the air inflow end side toward the air outflow end side, and the first rail The width is the second and third from the air inflow end side.
The rail width of the second rail is parallel to the longitudinal direction of the floating head slider, and the length of the parallel portion is the length of the first rail. 30% or more of the floating head slider according to claim 1. 3. The rail width of the first rail is at least 2 from the air inflow end side toward the air outflow end side.
The rail width of the first step is 70% or more of the entire length from the air inflow end parallel to the slider longitudinal direction, and the rail width of the second step monotonically increases toward the air outflow end side. And the widths of the second and third rails are bilaterally symmetrical, and the rail widths thereof change in at least two steps, and monotonically decrease from the air inflow end toward the air outflow end. It has comprised so that it may be constituted.
Floating head slider as described. 4. The method for manufacturing a floating head slider according to claim 2, wherein the first to the first of the floating head sliders are used.
A method of manufacturing a floating head slider, comprising a step of processing a third rail with one type of grinding blade (blade).