A suspension for a disk device, a disk device, and a manufacturing method for a suspension for a disk device

Abstract

A magnetic disk device suspension according to an embodiment includes a load beam, a load arm having a load arm portion to which a slider is mounted, and a flexure superimposed on the load beam. The load beam has a tab extending in a longitudinal direction of the load beam and protruding from the load arm portion, the tab having a curved shape such that a central portion in a lateral direction of the load beam is more convex than both end portions in the lateral direction, the both end portions each having a flat surface parallel to the lateral direction.

Description

[0001] Cross-reference (reference to related applications)

[0002] This application is based on a prior application filed in Japan on October 1, 2021 (Japanese Patent Application No. 2021-162717), and enjoys priority from all matters disclosed in the prior application. Technical Field

[0003] The present invention relates to a magnetic disk device suspension used in a hard disk drive or the like, a magnetic disk device, and a method for manufacturing the magnetic disk device suspension. Background Art

[0004] Hard disk drives (HDDs) are used in information processing devices such as personal computers. They consist of a magnetic disk that rotates around a spindle and a carriage that pivots around a pivot. The carriage has an actuator arm and is rotated about the pivot in the direction of the magnetic disk's track width by a positioning motor such as a voice coil motor.

[0005] The actuator arm is provided with a suspension for a magnetic disk device (hereinafter referred to as the suspension). The suspension includes a load beam and a flexure superimposed on the load beam. A slider constituting a magnetic head is provided on a universal joint formed near the front end of the flexure. The slider has an element (converter) for accessing, such as reading or writing data. These load beams, flexures, and sliders constitute a magnetic head universal joint assembly.

[0006] To increase disk recording density, the head gimbal assembly needs to be made more compact, and the slider needs to be positioned on the disk's recording surface with greater precision. Furthermore, due to the strong demand for increasing the recording capacity of hard disk devices to increase recording density, there is a trend toward increasing the number of disks contained in hard disk devices (i.e., multi-disk).

[0007] To increase the number of disks, not only do the disks need to be thinner, but the distance between them also needs to be reduced. Reducing the distance between the disks increases the risk of contact between the suspensions that face each other between the disks. Therefore, the suspensions need to be made thinner and lighter.

[0008] For example, Japanese Patent Publication No. 2020-129423 discloses a magnetic disk device capable of increasing the number of magnetic disks installed as recording media. However, even with the suspension included in the magnetic disk device described in Reference 1, there is a risk that the front end blades of the opposing suspensions may contact each other as the number of magnetic disks increases. Summary of the Invention

[0009] One of the objects of the present invention is to provide a suspension for a magnetic disk device, a magnetic disk device, and a method for manufacturing the suspension for a magnetic disk device, which can cope with the demand for an increase in the number of magnetic disks.

[0010] A suspension for a magnetic disk apparatus according to an embodiment includes a load beam, a mounting portion that mounts a slider, and a flexure that is stacked on the load beam. The load beam has a tab that extends in a longitudinal direction of the load beam and protrudes from the mounting portion, and the tab has a curved shape such that a central portion in a lateral direction of the load beam is more convex than both end portions in the lateral direction. The both end portions have flat surfaces that are parallel to the lateral direction.

[0011] The tab has a first surface that is a circular arc shape on a thickness direction of the load beam that intersects the longitudinal direction and the lateral direction and is on the flexure side, and a second surface that is a circular arc shape opposite the first surface. The flat surfaces can be connected to the second surfaces, respectively. The both end portions can further have connecting surfaces that connect the first surfaces and the flat surfaces.

[0012] The both end portions further have a first edge that connects the first surface and the connecting surface, and a second edge that connects the flat surface and the connecting surface. A distance from the first edge to the second edge in the thickness direction can be less than or equal to half of a thickness between the first surface and the second surface.

[0013] A manufacturing method of a suspension for a magnetic disk apparatus according to an embodiment is a manufacturing method of a suspension for a magnetic disk apparatus that has a load beam with a tab, including a bending process that forms a metal plate into a curved shape such that a central portion in a lateral direction of the tab is more convex than both end portions in the lateral direction, and a flattening process that forms flat surfaces that are parallel to the lateral direction at the both end portions.

[0014] The metal plate includes a third surface that is formed into a circular arc shape in the bending process, a fourth surface that is formed into a circular arc shape opposite the third surface in the bending process, a fifth surface that is connected to the third surface and the fourth surface, and an edge that is connected to the fourth surface and the fifth surface. In the flattening process, the edge can be flattened.

[0015] A magnetic disk device according to an embodiment includes a first disk, a second disk opposed to the first disk with a space therebetween, a first suspension that performs reading or writing of data to the first disk, a second suspension that performs reading or writing of data to the second disk, and a ramp provided at an outer periphery side of the first disk and the second disk with a space therebetween. The first suspension and the second suspension include a load beam, a mounting portion that has a mounting carriage and is superimposed on the load beam, and a flexure that is superimposed on the load beam. The load beam has a wing that extends in a longitudinal direction of the load beam and protrudes from the mounting portion. The wing has a curved shape such that a central portion in a lateral direction of the load beam is convex than both end portions in the lateral direction, and the both end portions each have a flat surface parallel to the lateral direction. When the mounting portions are retracted from the first suspension and the second suspension, respectively, the flat surfaces of the first suspension and the second suspension are positioned in a state of being opposed to each other with a gap therebetween in the gap.

[0016] According to the suspension for a magnetic disk device, the magnetic disk device, and the manufacturing method of the suspension for a magnetic disk device configured as described above, it is possible to cope with a demand for an increase in the number of disks. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the current preferred embodiments of the application and, together with the description, serve to explain the principles of the application.

[0018] Figure 1 A simple perspective view showing an example of a magnetic disk device is shown.

[0019] Figure 2 A simple cross-sectional view showing a part of a magnetic disk device is shown.

[0020] Figure 3 A simple perspective view showing a part of a suspension viewed from a slider side is shown.

[0021] Figure 4 A cross-sectional view of a wing taken along line IV-IV of FIG. 4 is shown. Figure 3

[0022] Figure 5 A simple perspective view showing a relation between a wing and a ramp when the suspension is retracted to the ramp is shown.

[0023] Figure 6 A simple perspective view showing an example of a thickness of a wing in a thickness direction is shown.

[0024] Figure 7 A simple perspective view showing another example of a thickness of a wing in a thickness direction is shown.

[0025] Figure 8 A simple perspective view showing an example of a manufacturing method of a wing is shown.​

[0026] Figure 9 An example of a manufacturing method of a wing is shown.

[0027] Figure 10 An example of a manufacturing method of a wing is shown.

[0028] Figure 11 Another example of a manufacturing method of a wing is shown.

[0029] Figure 12 Another example of a manufacturing method of a wing is shown. DETAILED DESCRIPTION

[0030] Figure 1 is a schematic perspective view showing an example of a magnetic disk device (HDD) 1. The magnetic disk device 1 includes a housing 2, a plurality of magnetic disks (hereinafter referred to as disks 4) rotating around a spindle 3, a carriage 6 capable of turning around a pivot 5, a positioning motor (voice coil motor) 7 driving the carriage 6, and a ramp 9 mounted to the housing 2. The ramp 9 is provided at an outer peripheral side of the disks 4. The housing 2 is sealed with a lid (not shown).

[0031] Figure 2 is a schematic sectional view showing a part of the magnetic disk device 1. As shown in Figure 1 and Figure 2 , a plurality of arms (carriage arms) 8 are provided on the carriage 6. A suspension 10 is mounted to a distal end of each of the arms 8. A slider 11 constituting a magnetic head is provided at a front end portion of each of the suspensions 10.

[0032] When the disks 4 rotate at high speed, air flows between the disks 4 and the sliders 11, forming an air bearing. When the carriage 6 rotates by the positioning motor 7, the suspensions 10 move the sliders 11 to desired tracks on the disks 4 by moving in a radial direction of the disks 4.

[0033] When the disks 4 stop, the suspensions 10 retract toward the ramp 9 as shown in Figure 1 . When the disks 4 are driven, the suspensions 10 retracted to the ramp 9 move from the ramp 9 toward the disks 4.

[0034] As shown in Figure 2 , the disks 4 have a first disk 4A and a second disk 4B. The first disk 4A and the second disk 4B have a spacing therebetween and face each other. From another perspective, the first disk 4A faces the second disk 4B in a thickness direction of the housing 2. The first disk 4A has a surface 40A, and the second disk 4B has a surface 40B facing the surface 40A.

[0035] The plurality of suspensions 10 provided in the disk device 1 includes a first suspension 10A and a second suspension 10B. The first suspension 10A and the second suspension 10B are located between the first disk 4A and the second disk 4B. The first suspension 10A faces the second suspension 10B in the thickness direction of the housing 2.

[0036] The first suspension 10A has a slider 11A for reading data from or writing data to the surface 40A of the first disk 4A. The second suspension 10B has a slider 11B for reading data from or writing data to the surface 40B of the second disk 4B. The number of disks 4 is not limited to two, but can be three or more. The number of suspensions 10 is appropriately changed according to the number of disks 4.

[0037] Figure 3 is a schematic perspective view of a portion of the front end side of the suspension 10 viewed from the slider 11 side. The suspension 10 includes a base plate (not shown) fixed to the arm 8 of the carriage 6 (as shown in Figure 1 and 2 , a load beam 21, and a flexure 22 stacked on the load beam 21. The flexure 22 is arranged along the load beam 21. The flexure 22 is fixed to the load beam 21 by laser spot welding or the like.

[0038] The load beam 21 and the flexure 22 both extend in the longitudinal direction of the suspension 10. In the following, the longitudinal direction of the suspension 10, the load beam 21, and the flexure 22 is defined as the longitudinal direction X, and the direction (lateral direction) perpendicular to the longitudinal direction X is defined as the lateral direction Y of the suspension 10, the load beam 21, the flexure 22, and the like.

[0039] The direction intersecting (for example, perpendicular to) the longitudinal direction X and the lateral direction Y is defined as the thickness direction Z of the suspension 10, the load beam 21, the flexure 22, and the like. As indicated by the circular arc-shaped arrow near the front end of the load beam 21, the swing direction S is defined.

[0040] An element 12 capable of converting a magnetic signal and an electric signal like an MR element is provided at the front end portion of the slider 11 constituting the head. These elements 12 are used to perform an access operation such as reading data from or writing data to the disk 4. The slider 11, the load beam 21, the flexure 22, and the like constitute a head gimbal assembly.

[0041] The load beam 21 has a surface 21a. The flexure 22 is arranged on the surface 21a. The flexure 22 is stacked on the main body portion 21A of the load beam 21. The flexure 22 has a metal base 30 made of a thin stainless steel plate and a wiring portion 41 arranged along the metal base 30. A part of the wiring portion 41 is electrically connected to the element 12 of the slider 11 via a terminal 41a of the slider 11.

[0042] The thickness of the metal base 30 is smaller than the thickness of the load beam 21. The thickness of the metal base 30 is preferably 12 to 25 μm, and in one example, 20 μm. The thickness of the load beam 21 is, for example, 30 μm.

[0043] The flexure 22 has a tongue 31, a first overhang 32, and a second overhang 33. The slider 11 is mounted on the tongue 31. The tongue 31 is one example of a mounting portion that mounts the slider 11.

[0044] The first overhang 32 and the second overhang 33 are provided on both sides in the lateral direction Y of the tongue 31. The first overhang 32 and the second overhang 33 are formed in a shape that protrudes outward from both sides of the tongue 31 in the lateral direction Y. The tongue 31, the first overhang 32, and the second overhang 33 are all portions of the metal base 30, and are formed in profile by, for example, etching.

[0045] A shallow recess (not shown) that protrudes toward the tongue 31 is formed near the front end of the main portion 21A of the load beam 21. The front end of the shallow recess is in contact with the tongue 31. The tongue 31 can swing around the front end of the shallow recess to perform a desired gimbal motion. The gimbal portion 50 is composed of the tongue 31, the first overhang 32, the second overhang 33, the shallow recess, and the like.

[0046] The first micro actuator 51 and the second micro actuator 52 are mounted on the gimbal portion 50. The micro actuators 51 and 52 have a function of rotating the tongue 31 in a swing direction.

[0047] The micro actuators 51 and 52 are arranged on both sides of the slider 11 in the lateral direction Y. The micro actuators 51 and 52 are made of a piezoelectric material such as lead zirconate titanate (PZT).

[0048] Both end portions 51a and 51b of the first micro actuator 51 are fixed to actuation support portions 34 and 35 of the tongue 31 by a conductive adhesive or the like, respectively. Both end portions 52a and 52b of the second micro actuator 52 are fixed to actuation support portions 36 and 37 of the tongue 31 by a conductive adhesive or the like, respectively. The main portion 21A of the load beam 21 has a front end portion 21b on the opposite side from the one end portion that is connected to the base plate. The load beam 21 is formed with a tab 60 that extends and protrudes from the front end portion 21b in the longitudinal direction X. The tab 60 is guided to move the suspension 10 to a retracted position when the magnetic disk 4 is stopped.

[0049] The tab 60 is integrally formed with the main portion 21A of the load beam 21. As shown in FIG. 2, the tab 60 has an elongated shape that extends in the longitudinal direction X. The tab 60 extends in the longitudinal direction X and protrudes from the tongue 31. Figure 3

[0050] ​The wing 60 has an end portion 60a, an end portion 60b opposite to the end portion 60a, and a central portion 60c in the transverse direction Y. The central portion 60c is located between the end portions 60a and 60b in the transverse direction Y. Hereinafter, the end portions 60a and 60b will be collectively referred to as "the two end portions 60a, 60b."

[0051] Figure 4 It is along Figure 3 FIG. 5 is a cross-sectional view of the fin 60 taken along line IV-IV. The fin 60 is formed into an arc shape that curves toward the flexure 22 in the thickness direction Z. The expression "the fin 60 curves toward the flexure 22" means that the fin 60 curves in the thickness direction Z from the surface opposite to the surface 21a of the load beam 21 toward the surface 21a ( Figure 4 More specifically, as Figure 4 As shown, the fin 60 has a shape in which the central portion 60c is more convex than the end portions 60a and 60b.

[0052] The fin 60 has an arcuate surface 61 (first surface) and an arcuate surface 62 (second surface) opposite to surface 61. Both ends 60a and 60b have a flat surface 63 connected to surface 62 and a connecting surface 64 connecting surface 61 and flat surface 63. Surface 61 is located on the flexure 22 side in the thickness direction Z (the same side as surface 21a of the main body 21A of the load beam 21). The fin 60 curves from surface 62 toward surface 61 in the thickness direction Z. The centers of curvature of surfaces 61 and 62 are located on the surface 62 side in the thickness direction Z.

[0053] At both ends 60a, 60b of the wing 60, flat surfaces 63 are formed along the longitudinal direction X. The flat surface 63 is formed integrally from the base end to the front end of the wing 60 connected to the main body portion 21A. Figure 4 As shown, the flat surface 63 is a surface parallel to the transverse direction Y. Here, "parallel to the transverse direction Y" includes a situation where it is slightly inclined relative to the transverse direction Y. In addition, the flat surface 63 may also be a surface parallel to the longitudinal direction X.

[0054] The distance between the flat surface 63 of both end portions 60a, 60b and the surface 61 in the thickness direction Z decreases as the distance from the central portion 60c increases in the transverse direction Y. The connecting surface 64 is formed at both end portions 60a and 60b of the wing 60 in the longitudinal direction X. Figure 4 In the example shown, the connecting surface 64 is a surface that is inclined relative to the flat surface 63. From another perspective, the flat surface 63 is connected to the surface 61 via the connecting surface 64.

[0055] Figure 5 1 is a diagram showing the relationship between the fin 60 and the slope 9 when the suspension 10 is retracted toward the slope 9 . Figure 5A portion of the cross section of the fin 60 and the ramp 9 viewed from the front end side of the fin 60 is shown. For example, Figure 5 is a state in which the tongue 31 with the slider 11 is retracted from the first disk 4A and the second disk 4B.

[0056] In Figure 5 the example shown, the ramp 9 has two support surfaces 90 and a gap 91 formed between the two support surfaces 90. The ramp 9 is made of, for example, synthetic resin. The fins 60 of the first suspension 10A and the fins 60 of the second suspension 10B are respectively positioned in the gap 91.

[0057] The fins 60 are each supported on the support surfaces 90 of the gap 91. The surfaces 61 are each in contact with the support surfaces 90 at the central portions 60c of the fins 60. The surfaces 62 and the flat surfaces 63 of the first suspension 10A and the surfaces 62 and the flat surfaces 63 of the second suspension 10B are spaced apart in the thickness direction Z and face each other. In this case, the flat surfaces 63 are closest to each other.

[0058] As Figure 5 shown, the flat surfaces 63 are parallel to each other. A gap G is formed between the flat surfaces 63. From another perspective, the flat surfaces 63 of the first suspension 10A are not in contact with the flat surfaces 63 of the second suspension 10B.

[0059] When the flat surfaces 63 and the connecting surfaces 64 are not formed on the fins 60, the shapes of the end portions 60b of the fins 60 of the suspensions 10A and 10B are indicated by dotted lines. If the flat surfaces 63 are not formed, the fins 60 can be in contact with each other at positions indicated by an arrow P in, for example, Figure 5

[0060] Figure 6 is an example view showing the thickness T60 of the fin 60 in the thickness direction Z. As Figure 6 shown, the both end portions 60a, 60b have an edge 65 (first edge) connected to the surface 61 and the connecting surface 64 and an edge 66 (second edge) connected to the flat surface 63 and the connecting surface 64. As Figure 6 indicated by a dotted line in, the intersection of the extending surface 62 and the connecting surface 64 is defined as an edge M67. The fin 60 has the edge M67 when the flat surface 63 is not formed. At Figure 5 positions indicated by an arrow P in, the edges M67 are in contact with each other.

[0061] ​Here, the distance in the thickness direction Z from the edge 65 to the edge 66 is set as a distance h. The distance h can also be said to be the protruding height of the edge 66 with respect to the edge 65. The thickness between the surfaces 61 and 62 is set as a thickness t. The distance between the edges 65 of the both end portions 60a and 60b in the lateral direction Y is set as a distance W, and the radius of curvature of the surface 62 is set as a radius of curvature R. The distance h is preferably, for example, half or less of the thickness t (t / 2 > h).

[0062] By providing the distance h as described above, as shown in Figure 6 the thickness T60 of the fin 60 in the thickness direction Z can be made smaller than the thickness T600 of the fin 60 when the flat surface 63 is not formed. Further, by reducing the thickness T60 of the fin 60 in the thickness direction Z, the length of the flat surface 63 in the lateral direction Y can be increased. By increasing the length of the flat surface 63 in the lateral direction Y, the area of the flat surface 63 in the longitudinal direction X and the lateral direction Y can be increased.

[0063] Figure 7 is another example diagram showing the thickness T60 of the fin 60 in the thickness direction Z. In this example, the distance in the thickness direction Z from the edge 65 to the edge M67 is defined as a distance H. The distance h is preferably, for example, half or less of the distance H (H / 2 > h).

[0064] By making the distance h half or less of the distance H, the thickness T60 of the fin 60 can be further reduced. Further, by reducing the thickness T60 of the fin 60 in the thickness direction Z, the length of the flat surface 63 in the lateral direction Y can be made longer.

[0065] In Figure 6 and Figure 7 the example shown, the thickness t is, for example, 0.030 mm, the distance W is 0.250 mm, the radius of curvature R is 0.160 mm, the distance H is 0.023 mm, and the distance h is 0.008 mm. Each dimension is not limited to the above size example.

[0066] Next, the manufacturing method of the suspension 10 having the load beam 21 with the fin 60 will be described. The metal plate in a flat state as a material of the load beam 21 is pre-trimmed to a predetermined shape. The load beam 21 can be formed by pressing the trimmed metal plate using a mold assembly.

[0067] The fin 60 of the load beam 21 is formed in a curved shape, for example, by embossing processing using a mold assembly. Hereinafter, the manufacturing method of the fin 60 in the manufacturing method of the suspension 10 will be mainly described.

[0068] Figure 8 to Figure 10 is an example diagram showing the manufacturing method of the fin 60. Figure 8The cross section of the portion of the metal plate M that forms the fin 60 is shown in the subsequent drawings. The longitudinal direction, the lateral direction, and the thickness direction of the metal plate M coincide with the longitudinal direction X, the lateral direction Y, and the thickness direction Z of the load beam 21. As shown in Figure 6 The thickness t shown is equivalent to the thickness of the metal plate M.

[0069] As shown in Figure 8 The metal plate M has a surface M61 (3rd surface) that forms the surface 61, a surface M62 (4th surface) that forms the surface 62, a surface M68 (5th surface) that is continuous with the surface M61 and the surface 62, and an edge M67 that is continuous with the surface M62 and the surface M68, as shown in Figure 6 and Figure 7 The edge M67 shown.

[0070] The metal plate M has an end portion Ma, an end portion Mb opposite the end portion Ma, and a central portion Mc in the lateral direction Y. The central portion Mc is located between the end portion Ma and the end portion Mb in the lateral direction Y. Hereinafter, the end portion Ma and the end portion Mb are sometimes collectively referred to as "both end portions Ma, Mb". The end portion Ma will form the end portion 60a, the end portion Mb will form the end portion 60b, and the central portion Mc will form the central portion 60c.

[0071] The manufacturing method of the fin 60 has a bending process and a flattening process. In the bending process, the metal plate M is, for example, press worked using a die assembly, so that the metal plate M is formed into a circular arc shape. As shown in Figure 9 By the bending process, the metal plate M has a curved shape in which the central portion Mc is convex with respect to both end portions Ma and Mb, as shown in

[0072] In the flattening process, for example, the edge M67 is pressed in the thickness direction Z toward the surface M61 using a die assembly, so that the edge M67 is crushed and flattened, thereby forming a flattened surface 63, as shown in Figure 10 Hereinafter, the process of crushing a portion of the metal plate M is referred to as "crushing work". In both end portions Ma and Mb, for example, the crushing work of the edge M67 is performed simultaneously. The flattened surface 63 is thereby formed, for example, to have a predetermined surface texture.

[0073] The flattened surface 63 is formed in both end portions Ma and Mb of the metal plate M in the longitudinal direction X. As shown in Figure 10 The flattened surface 63 is parallel to the lateral direction Y, and the edge M67 is crushed. In addition, the flattened surface 63 can also be a surface parallel to the longitudinal direction X.

[0074] When the flattened surface 63 is formed, a connecting surface 64 is also formed. The connecting surface 64 is a portion of the surface M68. The connecting surface 64 is shaped by the crushing work of the edge M67 in the flattening process. The connecting surface 64 is, for example, a surface inclined with respect to the flattened surface 63.

[0075] The metal plate M is manufactured into the fin 60 by the above manufacturing method. The flattening process can be performed before the bending process, after the bending process, or simultaneously with the bending process. Thereafter, the flexure 22 is superimposed on the load beam 21 at a predetermined position.

[0076] Figure 11 and Figure 12 is another example diagram showing a manufacturing method of the fin 60. For example, the surfaces M62 and M68 around the edge M67 are chamfered by an etching process before the bending process. From another perspective, the edge M67 is shaved off by the etching process. The etching process is performed, for example, when the metal plate is trimmed into a predetermined shape of the load beam 21 by etching.

[0077] By the etching process, the surface M69 connecting the surfaces M61 and M62 is formed on the metal plate M. The surface M69 has, for example, a curved surface. The etching process is included in the flattening process.

[0078] In the bending process, the metal plate M having the surface M69 is formed into a circular arc shape as shown in Figure 11 . In the flattening process, for example, as shown in Figure 12 , the surface M69 is pressed by using a mold assembly, so that a part of the surface M69 is crushed to form the flat surface 63. In both end portions Ma and Mb, for example, the crushing process of the surface M69 is performed simultaneously. The flat surface 63 is formed to have, for example, a surface property that is smoother than the surface M69. As shown in Figure 12 , the surface M69 is crushed so that the flat surface 63 is parallel to the lateral direction Y. Further, the flat surface 63 can also be a surface parallel to the longitudinal direction X.

[0079] When the flat surface 63 is formed, the connecting surface 64 is also formed. The connecting surface 64 is a part of the surface M69. In the flattening process, the surface M69 is crushed so that the connecting surface 64 is formed. The surface M69 can be formed by performing the etching process after the bending process. As described in Figure 8 to Figure 10 , the crushing process of the surface M69 can be performed before the bending process, after the bending process, or simultaneously with the bending process.

[0080] The fin 60 of the load beam 21 in the suspension 10 configured as described above has the flat surface 63. The thickness T60 of the fin 60 in the thickness direction Z is smaller than the thickness T600 of the fin 60 when the flat surface 63 is not formed. Thereby, it is possible to make it difficult for the fins 60 to contact each other, and to shorten the distance between the magnetic disks 4 and the distance between the support surfaces 90 of the ramps 9. From another perspective, even if the interval is smaller than in the past, it is difficult for the fins 60 to contact each other.

[0081] If the distance between the magnetic disks 4 is reduced, a greater number of magnetic disks 4 can be arranged in the same housing 2. As described above, the suspension 10 according to this embodiment can increase the number of magnetic disks.

[0082] The flat surfaces 63 of the fins 60 are connected to the surface 62 at both ends 60a and 60b, respectively. Thus, when the suspension 10 is retracted to the ramp 9, the flat surfaces 63 of the fins 60 can be spaced apart from each other and face each other in the gap 91 of the ramp 9.

[0083] If the fins 60 do not have Figure 6 If the flat surface 63 shown by the dotted line in FIG. 1 is not provided, the two end portions 60a and 60b may contact the gap 91. When the fin 60 has the flat surface 63, even if the distance between the support surfaces 90 is such that the two end portions 60a and 60b (particularly the edge 5467) are in contact with each other, the flat surfaces 63 can be arranged facing each other with a gap therebetween. From another perspective, the spacing between the support surfaces 90 can be made smaller.

[0084] If the magnetic disk device 1 is subjected to an external impact, the wings 60 of the suspension 10 may come into contact with each other. If the wings 60 have flat surfaces 63, the flat surfaces 63 will come into contact with each other. When the flat surfaces 63 come into contact with each other, particles such as dust are less likely to appear when the flat surfaces 63 come into contact with each other than when, for example, the edges 5467 come into contact with each other.

[0085] This can suppress damage to the magnetic disk 4 due to particles and prevent access failures such as when the slider 11 reads data from or writes data to the magnetic disk 4 .

[0086] Since the flat surface 63 is parallel to the transverse direction Y, the flat surface 63 is as shown in FIG. Figure 6 As shown, the flat surfaces 63 are parallel to each other. Therefore, it is easy for the flat surfaces 63 to make contact with each other, and particles are not easy to be generated. From another perspective, it is unlikely that the edges of the fins 60 will contact each other.

[0087] The tab 60 has a connecting surface 64 connecting the flat surface 63 and the surface 61. Therefore, the edge 65 is less likely to be sharp than the edge formed when the flat surface 63 and the surface 61 are directly connected.

[0088] If the distance h is made half the thickness t or less, the thickness T60 of the fin 60 can be made smaller. If the thickness T60 of the fin 60 is reduced, the distance between the magnetic disks 4 and the distance between the support surfaces 90 of the slope 9 can be further reduced. If the distance between the magnetic disks 4 can be made smaller, the number of magnetic disks can be further increased.

[0089] According to the manufacturing method of the suspension 10 according to the present embodiment configured as described above, the fins 60 having the flat surfaces 63 can be obtained. More specifically, by the flattening process, the flat surfaces 63 parallel to the lateral direction Y can be formed at both end portions 60a, 60b of the fins 60.

[0090] Since the flat surfaces 63 are formed by crushing using the die assembly, the flat surfaces 63 having high dimensional accuracy can be obtained in the fins 60 compared to chemical etching. Thus, when the fins 60 are positioned in the gap 91 of the ramp 90, sufficient spacing (gap) between the flat surfaces 63 can be ensured.

[0091] Further, by forming the flat surfaces 63 to have smooth surface texture, the occurrence of particles when the flat surfaces 63 contact each other can be further suppressed. By performing the flattening process simultaneously with the bending process, the flat surfaces 63 can be formed on the fins 60 without increasing the manufacturing processes. When the flattening process is performed before the bending process, since the edges M67 can be crushed by the metal die assembly with respect to the flat metal plate M, the flat surfaces 63 can be easily formed.

[0092] In the flattening process, the flat surfaces 63 can be formed by crushing the edges M67 of the metal plate M, or can be formed by crushing after the surface M69 is formed by the etching process.

[0093] After the surface M69 is formed by the etching process, the thickness T60 of the fins 60 can be further reduced by crushing the surface M69. By forming the surface M69 using the etching process, the crushing amount of the metal plate M in the crushing process is less compared to the crushing process when the surface M69 is not formed.

[0094] By reducing the crushing amount of the metal plate M by the die assembly, the burden on the die assembly is reduced. Thus, the maintenance period of the die assembly can be increased, and the burden on the operator can be reduced.

[0095] The disk device 1 according to the present embodiment having the suspension 10 can obtain a disk device 1 in which the number of disks 4 is increased, since the thickness T60 of the fins 60 of the suspension 10 is small. In addition to the above, various advantageous effects can be obtained according to the present embodiment.

[0096] According to the present embodiment, a suspension 10 that can cope with the demand for increasing the number of disks 4, a disk device 1 provided with the suspension 10, and a manufacturing method of the suspension 10 can be provided.

[0097] When implementing the invention disclosed in the above-described embodiments, the specific aspects of each element configuring the suspension for a disk device can be changed in various ways, including the shape of a load beam or a flexure, and the like. The connecting surface 64 can be, for example, a curved surface connecting the flat surfaces 63 and the surface 61.

[0098] In addition, in the flattening process of the manufacturing method of the wing 60, for example, the edge M67 can also be removed by laser to form the flat surface 63. As another example of the flattening process, Figure 11 As shown, the flat surface 63 can be formed by laser irradiation to form a flat surface on a portion of the surface M69 formed in the etching process. Laser irradiation can be performed before or after the bending process. By forming the flat surface 63 with laser, it is possible to form a flat surface 63 that is less likely to generate particles.

Claims

1. A suspension for a magnetic disc device, comprising: A load beam and a flexure having a mounting portion for mounting a slider and superposed on the load beam, The load beam has a tab extending in a longitudinal direction of the load beam and protruding from the mounting portion, The tab has a curved shape such that a central portion in a transverse direction of the load beam is more convex than both end portions in the transverse direction, The tab has a first surface of a circular arc shape on a side of the flexure and a second surface of a circular arc shape opposite to the first surface in a thickness direction of the load beam intersecting the longitudinal direction and the transverse direction, The both end portions have flat surfaces parallel to the transverse direction, the flat surfaces being connected to the second surface, the both end portions have connecting surfaces connecting the first surface and the flat surfaces, and The connecting surfaces are inclined from the flat surfaces to the first surface.

2. The suspension for a magnetic disk apparatus according to claim 1, the both end portions further having a first edge connecting the first surface and the connecting surface, and a second edge connecting the flat surface and the connecting surface, a distance from the first edge to the second edge in the thickness direction being less than or equal to half of a thickness between the first surface and the second surface.

3. The suspension for a magnetic disk apparatus according to claim 1, each of the both end portions further including a first edge and a second edge, the first surface and the connecting surface being connected at the first edge, the flat surface and the connecting surface being connected at the second edge, and a distance from the first edge to the second edge in the thickness direction being less than or equal to half of a thickness between the first edge and an intersection of the second surface and the connecting surface. A load beam and a flexure having a mounting portion for mounting a slider and superposed on the load beam, the load beam having a tab extending in a longitudinal direction of the load beam and protruding from the mounting portion; 4. A method of manufacturing a suspension for a disk drive, the suspension for a disk drive comprising: The manufacturing method includes a bending process and a flattening process, the bending process forming a metal plate into a curved shape such that a central portion in a transverse direction of the tab is more convex than both end portions in the transverse direction, the flattening process forming flat surfaces parallel to the transverse direction at the both end portions, respectively, wherein the tab has a first surface of a circular arc shape on a side of the flexure and a second surface of a circular arc shape opposite to the first surface in a thickness direction of the load beam intersecting the longitudinal direction and the transverse direction, the flat surfaces are connected to the second surface, and the flattening process includes connecting the first surface and the flat surfaces and inclining a connecting surface from the flat surfaces to the first surface.

5. The manufacturing method of the suspension for a magnetic disk apparatus according to claim 4, the metal plate including a third surface formed into a circular arc shape in the bending process, a fourth surface formed into a circular arc shape opposite to the third surface in the bending process, a fifth surface connected to the third surface and the fourth surface, and an edge connected to the fourth surface and the fifth surface, ​ In the flattening process, the edge is made flat so that the fifth surface becomes the connection surface.

6. The manufacturing method of a suspension for a magnetic disk apparatus according to claim 4, each of the two end portions further including a first edge and a second edge, the first surface and the connection surface being connected at the first edge, the flat surface and the connection surface being connected at the second edge, and In the flattening process, a distance in a thickness direction from the first edge to the second edge becomes smaller than or equal to half of a thickness between the first surface and the second surface.

7. The manufacturing method of a suspension for a magnetic disk apparatus according to claim 4, each of the two end portions further including a first edge and a second edge, the first surface and the connection surface being connected at the first edge, the flat surface and the connection surface being connected at the second edge, and In the flattening process, a distance in a thickness direction from the first edge to the second edge becomes smaller than or equal to half of a thickness between the first edge and an intersection of the second surface and the connection surface.

8. A magnetic disk apparatus comprising: a first magnetic disk, a second magnetic disk facing the first magnetic disk with a space therebetween, a first suspension that performs reading or writing of data to the first magnetic disk, a second suspension that performs reading or writing of data to the second magnetic disk, and ramps provided on outer periphery sides of the first and second magnetic disks with a space therebetween, the first and second suspensions including a load beam, a mounting portion that mounts a carriage, and a flexure that is superimposed on the load beam, the load beam having a wing that extends in a longitudinal direction of the load beam and protrudes from the mounting portion, the wing having a curved shape so that a central portion in a lateral direction of the load beam is convex more than both end portions in the lateral direction, the wing having a first surface that is a circular arc shape on a thickness direction of the load beam that intersects the longitudinal direction and the lateral direction and is on a side of the flexure, and a second surface that is a circular arc shape opposite the first surface, the both end portions each having a flat surface that is parallel to the lateral direction, the flat surface being connected to the second surface, the both end portions each having a connection surface that connects the first surface and the flat surface, and the connection surface being inclined from the flat surface toward the first surface, when the carriages are retracted from the first and second suspensions, respectively, the flat surfaces of the first and second suspensions are positioned in a state of facing each other with a gap therebetween in the gap.

9. The magnetic disk apparatus according to claim 8, each of the two end portions further including a first edge and a second edge, the first surface and the connection surface being connected at the first edge, the flat surface and the connection surface being connected at the second edge, and a distance in a thickness direction from the first edge to the second edge being smaller than or equal to half of a thickness between the first surface and the second surface.

10. The magnetic disk apparatus of claim 8, each of the two end portions further comprising a first edge and a second edge, the first surface and the connecting surface connecting at the first edge, the planar surface and the connecting surface connecting at the second edge, and a distance in the thickness direction from the first edge to the second edge is less than or equal to half of the thickness between the first edge and the intersection of the second surface and the connecting surface.

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