JP2005209340A - Slider and disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a slider capable of suppressing the variation of floating amount to a desired value or less over an entire disk radius, and securing a stable floating amount in all positions on a disk medium. <P>SOLUTION: An air lubricating surface 30A has an air inlet side pad 38 on the air inlet end 41 side of a recess 48 for generating negative pressure. In the 0 (rad) position of a skew angle made between a longitudinal axis supposed to pass through a slider center in a slider longitudinal direction and a disk rotational angle, V×(d/y)<1.5 is set where V(mm/s) is a relative speed between the slider and the disk medium, d(mm) is a step between the air inlet side pad and a rough plane formed on the air inlet end side of the air inlet side pad, and y(mm) is a distance from the air inlet end to the air inlet side pad. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a slider and a disk device, and more particularly to a slider that floats from a disk medium by an air flow between an air lubrication surface and the disk medium, and a disk device using the slider.

  In recent years, the data recording density of magnetic disk devices has been remarkably improved, and the increase in recording density is said to be 150% per year. Due to this remarkable increase in data recording density, the data recording capacity of the magnetic disk device has been dramatically improved. The increase in data recording capacity has prompted the miniaturization of magnetic disk devices, and various electronic devices such as cameras, facsimiles, cellular phones, modems, pagers, handheld computing devices, printers, copiers, etc. as disclosed in Patent Document 1. Cost-effective alternatives to these semiconductor memories are also becoming practical.

  Today's magnetic disk drives have a rotary actuator similar to the tone arm of a record player in order to obtain a high access speed. A slider is attached to the tip of the actuator arm. The surface of the slider facing the disk medium is an air-lubricated surface, and the slider draws the air flow generated as the disk medium rotates between the air-lubricated surface and the disk medium surface, thereby Has surfaced. That is, the slider forms and maintains a self-pressurizing air lubricant film between the disk medium storage surface. Therefore, the flying height of the slider with respect to the disk medium surface, that is, the distance between the disk medium surface and the slider is the thickness of the air lubricating film. This film makes it difficult for the slider and the disk medium to come into mechanical contact during rotation of the disk medium, thereby suppressing friction and wear.

  The slider has a built-in magnetic head for writing data to the disk medium or reading data from the disk medium. Generally, the magnetic head is disposed in the vicinity of the air outflow end of the air lubrication surface facing the disk medium of the slider.

  Further, by using the rotary actuator as described above, the sliding between the slider and the disk medium and the air flow under the slider are no longer unidirectional, and the longitudinal axis of the slider (through the center of the slider, It has various angles with respect to the slider or the axis imaginary in the longitudinal direction of the actuator. In addition, the high-speed search operation of the actuator being accessed also causes the sliding direction between the slider and the disk medium and the direction of the air flow flowing under the slider to be inclined with respect to the vertical axis. In a magnetic disk apparatus having an actuator, the sliding direction can no longer be considered to be a vertical axis direction from the front to the rear of the slider, or slightly deviated therefrom.

  Here, an angle formed by the sliding direction of the disk medium with respect to the longitudinal axis of the slider is called a skew angle. The skew angle is positive when the actuator arm is positioned so that the sliding direction is at or outside the disk media. The skew angle is negative when the actuator arm is positioned to hit the inner edge or hub of the disk media.

In a magnetic disk device, as the recording density increases, the flying height of the slider with respect to the disk medium when recording / reproducing tends to decrease. For example, as disclosed in Patent Document 2, Patent Document 3, Patent Document 4, and the like, the flying height is reduced by forming the air lubrication surface of the slider with a plurality of substantially flat surfaces having different heights. It is formed so as to generate a positive pressure (pressure acting in the direction of moving the slider away from the disk medium) on a substantially flat surface formed so as to reduce the gap with the medium, and to increase the gap between the slider and the disk medium. This is achieved by a so-called negative pressure type slider that generates a negative pressure (pressure acting in the direction in which the slider is brought closer to the disk medium) on a substantially flat surface, and floats the slider by balancing the positive pressure and the negative pressure. Is.
JP-A-8-249127 Japanese Patent No. 1505878 Japanese Patent No. 2778518 Japanese Patent No. 2880339

  As described above, when performing data access in the magnetic disk device, the slider moves in the range from the inner periphery of the disk medium to the outer periphery of the disk medium. In this case, the flying height and the flying attitude of the slider vary. This occurs on the air lubricated surface in a magnetic disk device having a rotary actuator because not only the relative speed of the slider and the disk medium varies depending on the radial position of the disk medium, but also the skew angle varies. This is because the air pressure distribution fluctuates. Such a flying height variation of the slider has a problem of deteriorating the electromagnetic conversion efficiency of the magnetic head. In particular, in a magnetic disk device that requires a high recording density, it is required that the flying height at the magnetic head position is uniform from the inner circumference to the outer circumference of the disk medium, and further, along with the lower flying height of the slider, Limitations on flying height fluctuations are also more strictly demanded.

  In addition, fluctuations in the flying position of the slider, particularly the roll angle fluctuation in the horizontal direction of the slider, cause a drop in the flying height at the minimum flying height position in a slider that requires constant flying at the magnetic head position described above. There is also a problem that the medium may come into contact and induce a so-called head crash.

  Further, in a magnetic disk device using a small-diameter disk medium having a diameter of 27 mm or the like that is currently being developed, for example, the relative speed between the slider and the disk medium is different from the magnetic disk apparatus using a disk medium having a diameter of 95 mm or 84 mm. Therefore, it is difficult to maintain a constant flying height and maintain a constant flying posture, which is a major problem in developing a small magnetic disk drive. ing.

  The present invention has been made to solve the above-mentioned conventional problems, and a slider capable of maintaining a constant flying posture and a constant flying height by suppressing the roll angle fluctuation and flying height fluctuation of the slider, and its An object is to provide a disk device using a slider.

  A slider according to a first aspect of the present invention includes a head for recording and / or reproducing data with a disk medium, and an air-lubricated surface having a recess for generating a negative pressure, and the air-lubricated surface and the disk In the slider that floats from the disk medium due to an air flow with the medium, the air lubrication surface is located on the air inflow end side of the recess and is an air inflow side pad that is the highest substantially flat surface on the air lubrication surface The relative velocity between the slider and the disk medium at a position where the skew angle formed between the vertical axis passing through the center of the slider and the virtual axis in the longitudinal direction of the slider and the disk rotation direction is 0 (rad) is V (mm). / S), and d (mm) is a step between the air inflow side pad and the substantially flat surface formed on the air inflow end side of the air inflow side pad, and the air inflow side pad from the air inflow end. If the distance were the y (mm) in, it is characterized in that V × (d / y) <1.5, a.

  According to the present invention, by suppressing an increase in the flying height at a position where the disk radius is larger than the track having a skew angle of 0 (rad), it is possible to suppress the flying height to less than a desired variation in the entire disk radius. As a result, it is possible to obtain a stable flying height at all positions on the disk medium.

  A slider according to a second aspect of the present invention is the slider according to the first aspect, wherein V × (d / y) <1.0.

  According to the present invention, the increase in the flying height at a position where the disk radius is larger than the track where the skew angle is 0 (rad) is smaller and stably suppressed, so that it is less than a desired flying height variation over the entire disk radius. Thus, it is possible to obtain an effect that a stable flying height can be secured at all positions on the disk medium.

  A slider according to a third aspect of the present invention is the slider according to the first aspect, wherein a substantially flat surface formed on the air inflow end side of the air inflow side pad extends to the air inflow end. Is.

  According to the present invention, a desired air-lubricating surface is formed, and thus an effect is obtained in which a stable flying height and a flying posture can be secured at all positions on the disk medium.

  According to a fourth aspect of the present invention, in the slider according to the first aspect, the air inflow side pad includes a cross rail extending in a horizontal axis direction of the slider.

  According to the present invention, it is possible to provide a slider in which a desired air-lubricating surface is formed and a flying height variation is suppressed in all regions on the disk medium.

  According to a fifth aspect of the present invention, there is provided a disk drive comprising the slider according to the first aspect.

  According to the present invention, it is possible to achieve an effect that a stable flying posture of the slider and suppressed flying fluctuation can be realized in the entire area of the disk medium.

  A disc device according to claim 6 of the present invention is characterized in that, in the disc device according to claim 5, the concave portion is formed symmetrically with respect to a longitudinal axis passing through the slider center and imaginary in the slider longitudinal direction. To do.

  According to the present invention, especially when the head is installed on the longitudinal axis of the slider, fluctuations in the roll angle can be limited to the minimum, and a stable flying height and flying posture can be ensured at all positions on the disk medium. A possible effect is obtained.

  The disk device according to claim 7 of the present invention is the disk device according to claim 5, wherein the air lubrication surface is formed symmetrically with respect to a longitudinal axis passing through the slider center and imaginary in the slider longitudinal direction. It is a feature.

  According to the present invention, especially when the head is installed on the longitudinal axis of the slider, fluctuations in the roll angle can be limited to the minimum, and a stable flying height and flying posture can be ensured at all positions on the disk medium. A possible effect is obtained.

  A disk device according to an eighth aspect of the present invention is characterized in that the disk device according to the fifth aspect complies with the PCMCIA standard.

  According to the present invention, there is an effect that it is possible to provide an ultra-compact disk device having high recording density and high reliability in accordance with the PCMCIA standard.

  A disk device according to a ninth aspect of the present invention is the disk device according to the fifth aspect, characterized in that it complies with the CompactFlash (registered trademark) standard.

  According to the present invention, there is an effect that it is possible to provide an ultra-compact disk device having high recording density and high reliability in accordance with the CompactFlash (registered trademark) standard.

  According to the slider of the first aspect of the present invention, the air-lubricated surface includes a head for recording and / or reproducing data with respect to the disk medium, and an air-lubricated surface having a recess for generating a negative pressure. In the slider which floats from the disk medium by the air flow between the disk medium and the disk medium, the air lubrication surface is located on the air inflow end side of the recess and is the air which is the highest substantially flat surface on the air lubrication surface. An inflow side pad, and the relative speed between the slider and the disk medium at a position where the skew angle formed by the vertical axis passing through the center of the slider and the virtual axis in the longitudinal direction of the slider and the disk rotation direction is 0 (rad). V (mm / s), d (mm) is a step between the air inflow side pad and a substantially flat surface formed on the air inflow end side of the air inflow side pad, and the air inflow side from the air inflow end When the distance to the head is y (mm), V × (d / y) <1.5, so the disk radius is larger than the track at the position where the skew angle is 0 (rad). By suppressing the increase in the flying height in the disk, it is possible to suppress the fluctuation in the flying height below a desired value over the entire disk radius, and it is possible to ensure a stable flying height at all positions on the disk medium. can get.

  According to the slider of the second aspect of the present invention, in the slider according to the first aspect of the present invention, V × (d / y) <1.0. Therefore, the disk radius has a skew angle of 0 (rad). ), The increase in the flying height at a position larger than the track at a position smaller than that of the track can be suppressed stably, so that it can be suppressed to a desired flying height fluctuation or less over the entire disk radius, and at all positions on the disk medium. An effect of ensuring a stable flying height can be obtained.

  According to a slider according to claim 3 of the present invention, in the slider according to claim 1, the substantially flat surface formed on the air inflow end side of the air inflow side pad extends to the air inflow end. Therefore, a desired air-lubricating surface is formed, so that an effect that a stable flying height and flying posture can be secured at all positions on the disk medium is obtained.

  According to the slider according to claim 4 of the present invention, in the slider according to claim 1, the air inflow side pad includes the cross rail extending in the horizontal axis direction of the slider. An effect of providing a slider in which an air lubrication surface is formed and the flying height fluctuation is suppressed in all regions on the disk medium can be obtained.

  According to the disk device of the fifth aspect of the present invention, since the slider according to the first aspect is provided, a stable flying posture of the slider and a suppressed flying fluctuation can be realized in the entire area of the disk medium. The effect is obtained.

  According to a disk device according to a sixth aspect of the present invention, in the disk device according to the fifth aspect, the recess is formed symmetrically with respect to a longitudinal axis passing through the slider center and imaginary in the slider longitudinal direction. Therefore, especially when the head is installed on the vertical axis of the slider, fluctuation of the roll angle can be limited to a minimum, and a stable flying height and flying posture can be secured at all positions on the disk medium. The effect becomes.

  According to a disk device according to a seventh aspect of the present invention, in the disk device according to the fifth aspect, the air lubrication surface is formed symmetrically with respect to a longitudinal axis passing through the slider center and imaginary in the slider longitudinal direction. Therefore, especially when the head is installed on the vertical axis of the slider, the fluctuation of the roll angle can be limited to the minimum, and a stable flying height and flying posture can be secured at all positions on the disk medium. A possible effect is obtained.

  According to the disk device according to claim 8 of the present invention, since the disk device according to claim 5 is based on the PCMCIA standard, the recording density based on the PCMCIA standard is high and the reliability is high. There is an effect that an ultra-small disk device can be provided.

  According to the disk device according to claim 9 of the present invention, the disk device according to claim 5 conforms to the CompactFlash (registered trademark) standard, and therefore conforms to the CompactFlash (registered trademark) standard. Thus, there is an effect that it is possible to provide an ultra-small disk device with high recording density and high reliability.

(Embodiment 1)
Hereinafter, a slider and a disk device according to Embodiment 1 of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing the inside of the magnetic disk device. FIG. 2 is a cross-sectional view showing the magnetic disk device. The magnetic disk device has a housing cover (not shown), and the disk medium 2 and the slider 3 are covered by the housing cover. The actuator arm set 5 is rotatably attached to the actuator shaft 20 and rotates around the actuator shaft 20 by the power of the voice coil motor 6. A suspension 14 is attached to the tip of each actuator arm group 5. A slider 3 having a magnetic transducer or a magnetic head (not shown in FIG. 1) is attached to the tip of each suspension 14.

  A main shaft 1 is mounted in the housing 7, and a large number of disk media 2 are rotatably attached to the main shaft 1 at intervals. The disk medium 2 rotates in the direction indicated by the arrow A in FIG. 1 together with the main shaft 1 rotated by the motor 8. The position of the magnetic head of the slider 3 with respect to the disk medium 2 is determined by the actuator arm set 5, and the magnetic head writes data to the disk medium 2 or reads data from the disk medium 2.

  The slider 3 and the magnetic head integrated therewith move on the surface of the disk medium 2 so that a magnetic representation of data can be stored in any track on the disk medium 2. In the magnetic disk apparatus, the head movement is caused by rotation around the actuator shaft 20. By rotating the actuator arm set 5, the slider 3 and the magnetic head therein can be positioned on any track on the surface of the disk medium 2.

  FIG. 3 is a schematic diagram showing one disk medium 2 and an actuator arm as viewed from above. As is well known in the art of magnetic disk devices, each disk medium 2 has concentric rows of tracks on which magnetic information is recorded. The inner diameter (ID) track 11 is the innermost concentric track in which data is stored. The outer diameter (OD) track 12 is the outermost concentric track in which data is stored. The sliding direction of the surface of the disk medium 2 with respect to the longitudinal axis 55 of the slider 3 (the rotation direction of the disk medium 2) is called a skew angle, and changes greatly from the ID track 11 to the OD track 12. It also depends on the mounting position of the actuator arm group 5 to the rotary actuator shaft 20. This skew angle can be positive or negative. The skew angle is said to be positive when the actuator arm set 5 is positioned so that the sliding direction is at the outer peripheral end 44 of the slider 3. When the actuator / arm set 5 is positioned so that the sliding direction corresponds to the inner peripheral end 43 of the slider 3, the skew angle is said to be negative. That is, with respect to FIG. 3, the skew angle is maximum in the OD track 12, is minimum in the ID track 11, and the skew angle is 0 degree in the medium diameter (MD) track 13. In the first embodiment, the radius of the medium disk at the outer diameter (OD) track 12 is 12.5 mm, the skew angle is 16 degrees, the radius at the inner diameter (ID) track 11 is 6 mm, and the skew angle is − The radius at 5 degrees, the medium diameter (MD) track 13 is 8.7 mm, and the rotation speed is 4500 rpm.

  FIG. 4 is a schematic diagram for explaining the flying posture of the slider 3 when the disk medium 2 is rotating constantly for recording and reproduction. The slider 3 is attached to the suspension 14 via a pivot 15.

  As shown in FIG. 4A, when the disk medium 2 is steadily rotating at a predetermined rotational speed for recording and reproduction, the slider 3 floats from the surface of the disk medium 2 and the magnetic head 99 is mounted. The flying posture is such that the flying height on the air outflow end 42 side is small. The inclination of the slider 3 in the direction of the vertical axis 55 with respect to the disk medium 2 is generally called a pitch angle. The pitch angle is positive when the flying height on the air outflow end 42 side is smaller than that on the air inflow end 41 side.

  Further, as shown in FIG. 4B, the inclination of the slider 3 in the direction of the horizontal axis 56 with respect to the disk medium 2 is called a roll angle. The roll angle is positive when the flying height on the disk outer peripheral end 44 side is smaller than that on the disk inner peripheral end 43 side.

FIG. 5A is a diagram showing the shape of the air-lubricated surface of the slider 3 according to the first embodiment, and FIG. 5B is a cross-sectional view showing an AA section of the air-lubricated surface.
The air lubrication surface 30 </ b> A in FIG. 5 is composed of three flat surfaces that are substantially parallel to each other, ie, an upper surface 31, an intermediate surface 32, and a lower surface 33. In FIG. 5, the drop between the upper step surface 31 and the middle step surface 32 is 100 nm, and the drop between the middle step surface 32 and the lower step surface 33 is 700 nm.

  The air inflow end 41 faces the direction in which the surface of the disk medium 2 rotates. The rotating disk medium 2 causes an air flow in the sliding direction of the disk medium 2 to flow from the air inflow end 41 under the air lubrication surface 30A due to a viscous effect. The pressure that acts in the direction of moving the slider 3 away from the disk medium 2 by the pressure generated on the air lubrication surface 30A by the air flow is called positive pressure, and the pressure that acts in the direction that brings the slider 3 closer to the disk medium 2 is called negative pressure. .

  On the air lubrication surface 30A, an air outflow side pad 34 for mounting the magnetic head 99 in the vicinity of the air outflow end 42 and an air inflow side pad 38 are constituted by the upper stage surface 31. The air inflow side pad 38 is spaced apart from the cross rail 35 formed at predetermined intervals from the inner peripheral end 43 and the outer peripheral end 44, and from the air inflow end 41, inner peripheral end 43, and air outflow end 42. The inner side rail 36 formed in this manner and the outer side rail 37 formed at a predetermined interval from the air inflow end 41, the outer peripheral end 44, and the air outflow end 42 are connected to each other. In addition, a middle step surface 32 is formed on the air inflow end 41 side of the air outflow side pad 34 and the air inflow side pad 38 to promote the inflow of air into the pads 34 and 38. A substantially flat surface of the middle cross section 32 formed on the air inflow end side of the air inflow side pad 38 extends to the air inflow end 41. A negative pressure generating recess 48 surrounded by the upper step surface 31 or the middle step surface 32 is formed by the lower step surface 33 at the center of the air lubrication surface 30A. The air lubrication surface 30 </ b> A according to the first embodiment is configured to generate a positive pressure mainly at the pads 34 and 38 and generate a negative pressure at the negative pressure generating recess 48.

  The air inflow end side ridge line (cross rail 35) and the outer peripheral side end ridge line (side rail 37) of the negative pressure generating recess 48 are connected by a ridge line having a receding angle θ with respect to the horizontal axis 56 assumed in the slider width direction. The air inflow end side ridge line (cross rail 35) and the inner peripheral side end ridge line (side rail 36) are connected by a ridge line having a receding angle η. In FIG. 5, θ = 0.2π (rad) and η = 0.2π (rad). However, in the present invention, θ and η can be changed to some extent. However, in order to obtain desired characteristics, θ and η need to be within a predetermined range. Hereinafter, this point will be described.

  FIG. 6 is a diagram showing a result of analyzing the roll angle when the slider 3 having the air lubricating surface 30A shown in FIG. 5 is positioned on the OD track 12 as a function of the receding angle θ. Note that the magnetic disk device used here has an allowable flying height variation of +/− 2 nm for a target flying height of 25 nm at the position of the magnetic head 99 and a roll allowed for a target roll angle of 0 μrad. Angular variation is +/− 10 μrad. FIG. 6 shows that the roll angle changes according to the receding angle θ, and can be controlled to be equal to or less than the desired roll angle variation in the first embodiment in the range of 0.14π <θ <0.28π.

  8 is a diagram showing the relationship between the roll angle and the receding angle θ at the OD track 12 for the air lubricated surface 30B shown in FIG. 7 and FIG. 10 for the air lubricated surface 30C shown in FIG. The steps of the upper surface 31, the intermediate surface 32, and the lower surface 33 of the air lubrication surfaces 30B and 30C are the same as those of the air lubrication surface 30A. It can be seen from FIG. 8 that the air lubricated surface 30B can be controlled to a desired roll angle fluctuation or less within a range of 0.19π <θ <0.30π, and FIG. 10 shows that the air lubricated surface 30C has 0.22π It can be seen that the desired roll angle fluctuation can be controlled within the range of <θ <0.38π.

  Here, in each of the air lubrication surfaces 30A, 30B, and 30C, the distance x from the air inflow end 41 to the negative pressure generating recess 48 is normalized by the length L of the slider to be X = x / L, and θ × X When the relationship between the roll angle and the roll angle is obtained, a noteworthy matter becomes clear. Hereinafter, this point will be described. Note that X of the air lubricated surfaces 30A, 30B, and 30C in the first embodiment is 0.405, 0.364, and 0.283, respectively.

FIG. 11 is a view showing the results shown in FIGS. 6, 8, and 10 together with θ × X as the horizontal axis. The symbol ● indicates the result of the air lubricated surface 30A, the symbol □ indicates the result of the air lubricated surface 30B, and the symbol ▲ indicates the result of the air lubricated surface 30C. According to FIG. 11, in all the air lubricated surfaces 30A, 30B, 30C, the ranges in which a desired roll angle is obtained are the same, and the value is 0.06π <θ × X <0.12π. That is, by forming a ridge line having a receding angle θ in a region where 0.06π <θ × X <0.12π, the roll angle of the slider 3 in a region where the skew angle is positive is made equal to or less than a desired roll angle fluctuation amount. By obtaining a stable flying attitude of the slider 3 in a region where the skew angle is positive, it is possible to secure a stable flying height at the minimum flying height position.
Furthermore, it can be seen from FIG. 11 that the optimum value of θ × X for suppressing the roll angle fluctuation is 0.09π.

  Next, roll angle control in a region where the skew angle is negative will be described. 12, 13, and 14 are diagrams showing the relationship between the roll angle and the receding angle η on the ID track 11 for the air lubricated surfaces 30A, 30B, and 30C, respectively. From FIG. 12, it can be seen that the air lubricated surface 30A can be controlled to a desired roll angle fluctuation or less in the range of 0.10π <η <0.35π. FIG. 13 shows that the air lubricated surface 30B has 0.12π It can be seen that the desired roll angle fluctuation can be controlled within the range of <η <0.38π, and FIG. 14 shows that for the air lubricated surface 30C, the desired roll angle is within the range of 0.20π <η <0.47π. It can be seen that control is possible below fluctuations.

FIG. 15 is a view showing the results shown in FIGS. 12, 13, and 14 together with η × X as the horizontal axis. The symbol ● indicates the result of the air lubricated surface 30A, the symbol □ indicates the result of the air lubricated surface 30B, and the symbol ▲ indicates the result of the air lubricated surface 30C. According to FIG. 15, in all the air lubricated surfaces 30A, 30B, and 30C, the ranges in which a desired roll angle is obtained are the same, and the value is 0.05π <η × X <0.13π. In other words, by forming a ridge line having a receding angle η in a region where 0.05π <η × X <0.13π, the roll angle of the slider 3 in the region where the skew angle is negative is made equal to or less than a desired roll angle fluctuation amount. By obtaining a stable flying posture of the slider 3 in a region where the skew angle is negative, it is possible to secure a stable flying height at the minimum flying height position.
Further, FIG. 15 shows that the optimum value of η × X for suppressing the roll angle fluctuation is 0.09π.

  FIG. 16 is a diagram showing a result of the roll angle of the ID track 11 and the OD track 12 on the air lubricated surface 30A on the relative speed dependency of the disk medium 2. The relative speed is represented by a value at the MD track 13 (skew angle 0 degree, radius 8.7 mm). From FIG. 16, it can be seen that when the roll angle needs to be controlled to +/− 10 μrad or less as in the first embodiment, it is desirable to use in a region where the relative speed is 13 m / s or less.

  In addition, in the slider 3 in which the magnetic head 99 is on the vertical axis 55 as in the first embodiment, negative pressure is generated so that the roll angle when positioned on the MD track 13 becomes zero. The recess 48 is preferably formed to be symmetric with respect to the longitudinal axis 55. Furthermore, it is desirable that the air lubrication surface 30 is symmetric with respect to the longitudinal axis 55.

  Further, the ridge line having the receding angle θ is formed on the outer peripheral side from the vertical axis 55 so that the ridge line having the receding angle θ does not affect the roll angle in the region where the skew angle is negative. It is desirable that the ridge line having the receding angle η is also formed on the inner peripheral side end side from the vertical axis 55 for the reason described above.

  Further, the receding angle θ and the receding angle η are the virtual line connecting the contact connected to the air inflow end side ridge line and the contact connected to the outer peripheral side end ridge line or the inner peripheral side end ridge line, and the horizontal axis 56. The ridgeline having the receding angle θ and the receding angle η is shown as a straight line in the first embodiment. However, the ridgeline is a curve in a range where the effect of the present invention can be substantially obtained. May be.

  As described above, according to the slider and the disk device according to the first embodiment, the ridge line on the air inflow end side and the ridge line on the disk outer peripheral side end are θ ( The negative pressure generating recess 48 is formed in the air lubrication surface 30 by being connected by a ridge line having a receding angle of rad), and a distance x from the air inflow end 41 of the air lubrication surface 30 to the negative pressure generating recess 48 is set. When X = x / L is normalized by the length L of the slider 3, θ × X is set to 0.06π to 0.12π to suppress roll angle fluctuation in a region where the skew angle is positive. It becomes possible to secure a stable flying height at the minimum flying height position.

  Also, negative pressure is generated by connecting the ridge line on the air inflow end side and the ridge line on the disk inner peripheral end with a ridge line having a receding angle of η (rad) with respect to the horizontal axis hypothesized in the slider width direction. When the recess 48 is formed in the air lubrication surface 30 and the distance x from the air inflow end 41 of the air lubrication surface 30 to the negative pressure generation recess 48 is normalized by the length L of the slider, X = x / L By setting η × X to 0.05π to 0.13π, it becomes possible to suppress the roll angle fluctuation in the region where the skew angle is positive, and to ensure a stable flying height at the minimum flying height position. It becomes possible.

(Embodiment 2)
Hereinafter, a slider and a disk device according to Embodiment 2 of the present invention will be described with reference to the drawings.
17 shows the flying height from the ID track 11 to the OD track 12 when the step d between the upper surface 31 and the middle surface 32 of the air lubricated surface 30A in FIG. 5 is 25 nm, 50 nm, 100 nm, 150 nm, and 200 nm. FIG. The mark ● indicates the step d is 25 nm, the mark □ indicates the step d 50 nm, the mark □ indicates the step d 100 nm, the mark □ indicates the step d 150 nm, and the mark * indicates the step d 200 nm. The relative speed between the slider 3 and the disk medium 2 on the MD track 13 at the steady rotational speed 4500 rpm of the disk medium 2 according to the first embodiment is 2π × 8.7 × (4500/60) ≈4100 mm / s = 4. .1 m / s. From FIG. 17, it can be seen that as the level difference d increases, the flying height of the OD track 12 tends to increase, and the difference between the flying height of the ID track 11 and the flying height of the OD track 12 increases.

  FIG. 18 is a diagram showing the relationship between the level difference d and the flying height fluctuation amount in the range of the ID track 11 to the OD track 12 for each of the air lubricated surfaces 30A, 30B, and 30C. From FIG. 18, it can be seen that the flying height fluctuation increases as the level difference d increases in all of the air lubricated surfaces 30A, 30B, and 30C.

  FIG. 19 is a diagram showing the relationship between the level difference d and the flying height fluctuation amount when the disk rotation speed is 4500 rpm and 9000 rpm for the air lubricating surface 30A. From FIG. 19, it can be seen that even if the rotational speed of the disk medium 2 (relative speed between the slider 3 and the disk medium 2) is different, the tendency of the flying height fluctuation to increase as the step d increases is the same. Furthermore, it can be seen from FIG. 19 that the higher the relative speed, the larger the flying height fluctuation in the range of the ID track 11 to the OD track 12.

  Here, the relative speed between the slider 3 and the disk medium 2 in the MD track 13 is V (mm / s), the distance from the air inflow end 41 to the air inflow side pad 38 is y (mm), and the horizontal axis is Taking V × (d / y) (hereinafter, V × (d / y) will be referred to as an adaptive coefficient α), and summarizing the flying height variation under each condition, a new tendency becomes clear. Strictly speaking, y is the distance from the air inflow end 41 to the front edge of the air inflow side pad 38, that is, the distance from the air inflow end 41 to the outer edge closest to the air inflow end 41 of the air inflow side pad 38. That is. Further, y = 0.41 mm for the air lubricated surface 30A, y = 0.35 mm for the air lubricated surface 30B, and y = 0.19 mm for the air lubricated surface 30C.

  FIG. 20 is a diagram illustrating the relationship between the adaptation coefficient α and the flying height variation amount for each of the air lubricated surfaces 30A, 30B, and 30C. The marks ●, ■, and ▲ indicate the results for the air-lubricated surfaces 30A, 30B, and 30C, respectively, at a steady rotational speed of 4500 rpm. 8.2 m / s). From FIG. 20, by using the flying height fluctuation amount as a function of the adaptation coefficient α, the results for all of the air lubricated surfaces 30A, 30B, and 30C are the same, and the flying height fluctuation amount in the ID track 11 to OD track 12 is 4 nm. It can be seen that the following (+/− 2 nm or less) is the region where the adaptation coefficient α is 1.5 or less. In addition, in the region where the adaptation coefficient α is 1.0 or less, the flying height fluctuation amount is approximately 2 nm (+/− 1 nm) or less and shows a substantially constant value. In addition, in the region where the adaptation coefficient α is larger than 2.0, the tendency that the flying height fluctuation amount in the ID track 11 to the OD track 12 rapidly increases is also consistent.

  Therefore, by configuring V, d, and y so that the adaptation coefficient α is 1.5 or less, preferably 1.0 or less, an increase in the flying height mainly at a position where the disk radius is larger than the MD track 13 is suppressed. Can be controlled within the range of the ID track 11 to the OD track 12 below the desired flying height fluctuation, so that a stable flying height can be secured at all positions on the disk medium 2 of the ID track 11 to OD track 12. It becomes possible to do.

  In the first embodiment, since the level difference d is set to 100 nm, the air lubricated surfaces 30A and 30B can obtain the effects of the present invention. However, the effect of the present invention can be obtained if the level difference d is 50 nm on the air lubrication surface 30C.

  Further, since the air lubrication surfaces 30A and 30B in the first embodiment have the receding angle θ, the receding angle η, and the adaptation coefficient α within the scope of the present invention, all of the ID track 11 to the OD track 12 on the disk are set. In the region, it is possible to maintain a stable flying height and a stable flying posture. Further, since the receding angle θ and the receding angle η are set in the above-described range also on the air lubricated surface 30C, it is possible to maintain a stable flying posture. Therefore, it can be seen that the magnetic disk drive equipped with the slider of the present invention suppresses head crashes and has better electromagnetic conversion efficiency and high reliability.

  As described above, according to the slider and the disk device according to the second embodiment, the relative speed between the slider 3 and the disk medium 2 in the MD track 13 is V (mm / s), and the air inflow side pad 38 and the air When the step from the substantially flat surface formed on the air inflow end side of the inflow side pad 38 is d (mm) and the distance from the air inflow end 41 to the air inflow side pad 38 is y (mm), V × ( By configuring V, d, and y so that (d / y) is 1.5 or less, it becomes possible to suppress the flying height fluctuation of the slider 3 depending on the relative speed. That is, the flying height fluctuation can be suppressed to a desired value or less in the entire range of the ID track 11 to the OD track 12, and a stable flying height can be maintained at all positions of the ID track 11 to the OD track 12. It becomes possible.

  Since V × (d / y) has a speed unit (mm / s), it is assumed that the adaptation coefficient α is physically a function of the friction speed. Therefore, in almost all magnetic disk devices at present, a lubricating film between the slider 3 and the disk medium 2 is formed of air. For example, in a nitrogen-filled disk device, an argon-filled disk device, etc., the optimum film is used. The adaptation coefficient α is not limited to the above. In this case, it can be inferred that the adaptation coefficient corresponding to each gas can be obtained by multiplying the ratio of the viscosity of each gas to the viscosity of air by the adaptation coefficient α shown here.

  Also, the air lubrication surfaces 30D to 30F shown in FIGS. 21 to 23 are configured with the receding angle θ, the receding angle η, and the adaptation coefficient α within the scope of the present invention. It is possible to suppress the roll angle fluctuation and the flying height fluctuation in the region, and to ensure a stable flying posture and a constant flying height. Here, the air lubrication surfaces 30D to 30F shown in FIGS. 21 to 23 do not include the cross rail 35 as shown in FIG. 5, but in this case as well, the same as the above-described embodiments. There is an effect. At this time, when the magnetic head 99 is on the vertical axis as shown in the first embodiment, it is desirable that the roll angle is as close to 0 as possible, so FIGS. 5, 7, 9, and 21 to 23 are used. As shown, if the negative pressure generating recess 48 and the air lubrication surface 30 are formed symmetrically with respect to the vertical axis, the roll angle in the MD track 13 can be made 0, and the ID track 11 to the OD track 12 In this area, the roll angle can be made close to zero.

  In addition, it has been described that the air lubrication surface 30 shown in each of the above embodiments is composed of three stages of the upper stage surface 31, the middle stage surface 32, and the lower stage surface 33, but this is designed in consideration of the current machining process. However, the air lubrication surface 30 should just be comprised by the arbitrary number of steps of two or more steps.

  In each of the above embodiments, the case where the slider 3 has the magnetic head 99 has been described. However, the slider 3 may have, for example, an optical head or a head such as a magnetoresistive element as a reproducing head. In the same manner, it is possible to realize a slider and a disk device that can ensure a stable flying posture and a constant flying height.

  Further, even in a small disk device configured in accordance with the PCMCIA standard or the CompactFlash (registered trademark) standard, it is possible to secure a stable flying posture and a constant flying height by using the slider of the present invention. Highly reliable data recording / reproduction is possible.

  As described above, the slider and the disk device according to the present invention record and / or reproduce data from and to the disk medium by floating from the disk medium by the air flow between the air lubrication surface and the disk medium. It is suitable for a slider and a disk device using the slider.

1 is a perspective view showing the inside of a magnetic disk device according to Embodiment 1 of the present invention. 1 is a cross-sectional view showing a magnetic disk device according to a first embodiment of the present invention. It is a schematic diagram which shows the one disk medium and actuator arm by Embodiment 1 of this invention. (A) And (b) is a schematic diagram for demonstrating the flying attitude | position of the slider by Embodiment 1 of this invention. (A) is a figure which shows the shape of the air lubrication surface by Embodiment 1 of this invention, (b) is a figure which shows the cross section of the air lubrication surface by Embodiment 1 of this invention. It is a figure which shows the relationship between receding angle (theta) and the roll angle in the air lubrication surface by Embodiment 1 of this invention. (A) is a figure which shows the shape of the air lubrication surface by Embodiment 1 of this invention, (b) is a figure which shows the cross section of the air lubrication surface by Embodiment 1 of this invention. It is a figure which shows the relationship between receding angle (theta) and the roll angle in the air lubrication surface by Embodiment 1 of this invention. (A) is a figure which shows the shape of the air lubrication surface by Embodiment 1 of this invention, (b) is a figure which shows the cross section of the air lubrication surface by Embodiment 1 of this invention. It is a figure which shows the relationship between receding angle (theta) and the roll angle in the air lubrication surface by Embodiment 1 of this invention. It is a figure which shows the relationship between (theta) xX and the roll angle in the air lubrication surface by Embodiment 1 of this invention. It is a figure which shows the relationship between receding angle (eta) and the roll angle in the air lubrication surface by Embodiment 1 of this invention. It is a figure which shows the relationship between receding angle (eta) and the roll angle in the air lubrication surface by Embodiment 1 of this invention. It is a figure which shows the relationship between receding angle (eta) and the roll angle in the air lubrication surface by Embodiment 1 of this invention. It is a figure which shows the relationship between (eta) xX and the roll angle in the air lubrication surface by Embodiment 1 of this invention. It is a figure which shows the relationship between the roll angle and relative speed in Embodiment 1 of this invention. It is a figure which shows the relationship between the flying height of the slider and disk radial position by Embodiment 2 of this invention. It is a figure which shows the relationship between the level | step difference d of the air lubrication surface by Embodiment 2 of this invention, and the flying height of a slider. It is a figure which shows the relationship between the level | step difference d of the air lubrication surface by Embodiment 2 of this invention, and the flying height of a slider. It is a figure which shows the relationship between the adaptive coefficient (alpha) and the flying height fluctuation amount in Embodiment 2 of this invention. (A) is a figure which shows the shape of an air lubrication surface, (b) is a figure which shows the cross section of an air lubrication surface. (A) is a figure which shows the shape of an air lubrication surface, (b) is a figure which shows the cross section of an air lubrication surface. (A) is a figure which shows the shape of an air lubrication surface, (b) is a figure which shows the cross section of an air lubrication surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main shaft 2 Disc medium 3 Slider 5 Actuator arm set 6 Voice coil motor 7 Housing 8 Motor 11 ID track 12 OD track 14 Suspension 20 Actuator shaft 30A, 30B, 30C, 30D, 30E, 30F Air lubrication surface 31 Upper surface 32 Middle step surface 33 Lower step surface 34 Air outflow side pad 35 Cross rail 36 Inner side rail 37 Outer side rail 38 Air inflow side pad 41 Air inflow end 42 Air outflow end 43 Inner peripheral side end 44 Outer peripheral side end 48 Negative pressure generating recess 55 Vertical axis 56 Horizontal axis 99 Magnetic head

Claims (9)

A disk for recording and / or reproducing data with a disk medium, and an air lubrication surface having a recess for generating a negative pressure, and the disk by an air flow between the air lubrication surface and the disk medium In the slider that floats from the medium,
The air lubrication surface is located on the air inflow end side of the recess, and has an air inflow side pad that is the highest substantially flat surface on the air lubrication surface,
The relative speed between the slider and the disk medium at a position where the skew angle between the vertical axis passing through the center of the slider and the virtual axis in the longitudinal direction of the slider and the disk rotation direction is 0 (rad) is V (mm / s), and The step between the air inflow side pad and the substantially flat surface formed on the air inflow end side of the air inflow side pad is d (mm), and the distance from the air inflow end to the air inflow side pad is y (mm). If
V × (d / y) <1.5,
The slider characterized by being. The slider according to claim 1,
V × (d / y) <1.0,
The slider characterized by being. The slider according to claim 1,
A substantially flat surface formed on the air inflow end side of the air inflow side pad extends to the air inflow end. The slider according to claim 1,
The slider, wherein the air inflow side pad includes a cross rail extending in a horizontal axis direction of the slider.   A disk device comprising the slider according to claim 1. The disk device according to claim 5, wherein
The disc device is characterized in that the recess is formed symmetrically with respect to a vertical axis passing through the center of the slider and hypothesized in the longitudinal direction of the slider. The disk device according to claim 5, wherein
The disk device according to claim 1, wherein the air lubrication surface is formed symmetrically with respect to a longitudinal axis passing through the center of the slider and hypothesized in the longitudinal direction of the slider. The disk device according to claim 5, wherein
A disk device characterized by conforming to the PCMCIA standard. The disk device according to claim 5, wherein
A disk device that conforms to the CompactFlash (registered trademark) standard.

Images