Spacer and hard disk drive device

Abstract

To provide a spacer for use in a hard disk drive device that suppresses deterioration of a flatness of a magnetic disk in a clamped state.SOLUTION: There is provided a circular glass spacer 1 that is provided in a hard disk drive device so that its main surface is in contact with a magnetic disk, the spacer including a pair of main surfaces 4, an inner peripheral surface 3, and an outer peripheral surface 2. A chamfered surface is provided between each of the pair of main surfaces and the outer peripheral surface, and at least one of the pair of the main surfaces has, in at least a part of its outer peripheral region, an inclined surface 1A inclined toward the other main surface in a radial direction from a center of the spacer toward the outer peripheral surface.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a magnetic disk drive provided in a hard disk drive device. The present invention relates to a circular ring-shaped spacer and a hard disk drive device. [Background technology]

[0002] With the recent rise of cloud computing, data centers for cloud computing In order to increase the storage capacity, many hard disk drive devices (hereinafter referred to as HDD devices) are being developed. Also called "Kyoto" (also called "Kyoto").

[0003] In the HDD device, the magnetic disks are separated from each other by a magnetic disk drive. A ring-shaped spacer is provided to hold the magnetic disk in place. The magnetic disks are precisely spaced apart so that they do not come into contact with each other and are precisely positioned at predetermined positions. It works. In HDD devices, spacers are placed between multiple magnetic disks to separate the magnetic disks and A spindle is inserted into the inner hole of the spacer to form a laminate of the magnetic disk and the spacer, and then clamped. The stack is pressed from one side with a clamping member, so that the magnetic disk and The spacer is fixed.

[0004] For example, the average surface roughness of the portion in contact with the information recording medium substrate is 0.001 to 0.005 μm. A glass spacer having a thickness of m is known (Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4136268 Summary of the Invention [Problem to be solved by the invention]

[0006] In a HDD device in which a magnetic disk is fixed using the spacer described above, It was found that the flatness of the main surface of the magnetic disk closest to the support member was significantly deteriorated. The deterioration of flatness is undesirable because it makes the magnetic disk more susceptible to fluttering when it rotates at high speed. In addition, contact between the ramp member, which is the retreating area for the magnetic head, and the magnetic disk occurs. This is not desirable as it makes the material more susceptible to damage.

[0007] Therefore, the present invention is to suppress the deterioration of the flatness of the magnetic disk in the clamped state. The object of the present invention is to provide a spacer for use in a hard disk drive device that controls the thickness of the disk. [Means for solving the problem]

[0008] One aspect of the present invention is a semiconductor device having a main surface in contact with a magnetic disk in a hard disk drive device. The spacer is an annular spacer provided so as to The spacer has a pair of main surfaces, an inner peripheral surface, and an outer peripheral surface. There is a chamfered surface between each of the grooves and the outer circumferential surface; At least a part of the outer circumferential region of at least one of the pair of main surfaces is A sloped area that slopes toward the other main surface in the radial direction from the center of the spacer toward the outer circumferential surface. It is characterized by having a region.

[0009] The amount of clearance of the inclined region inclined toward the other main surface is preferably 0.1 to 2 μm. It is.

[0010] the inclined region is a curved surface that is convex in a direction from the inside to the outside of the spacer; is preferred. It is preferable that the thickness of the magnetic disk is 80% or less of the thickness of the spacer. .

[0011] Preferably, the spacer material comprises glass.

[0012] the Young's modulus of the spacer is smaller than the Young's modulus of a substrate constituting the magnetic disk; It is preferred.

[0013] It is preferable that the spacer has a conductive film on its surface.

[0014] The magnetic disk preferably has a thickness of 0.55 mm or less.

[0015] Another aspect of the present invention is a hard disk drive including the spacer and the magnetic disk. It is a device.

[0016] Another aspect of the present invention is a hard disk drive including 10 or more magnetic disks and the spacer. The substrate of the magnetic disk is preferably made of glass. . Effect of the Invention

[0017] The above-mentioned spacer prevents the magnetic disk from being flat when it is clamped. It is possible to suppress the degradation. [Brief description of the drawings]

[0018] [Figure 1] 1 is a perspective view of an external appearance of a magnetic disk spacer according to an embodiment of the present invention; [Diagram 2] 1A and 1B are diagrams illustrating the arrangement of a spacer and a magnetic disk according to an embodiment. [Diagram 3]1 is a cross-sectional view of a main portion illustrating an example of the structure of an HDD device into which a spacer according to an embodiment is incorporated. [Figure 4] 4A to 4C are diagrams for explaining in detail the shape of the main surfaces of a spacer according to one embodiment. [Diagram 5] 1A and 1B are diagrams illustrating a state in which a magnetic disk is fixed by a top clamp in an HDD device. [Figure 6] 8 is a cross-sectional view of the spacer of the embodiment shown in FIG. 7 taken along line AA. [Figure 7] 1 is a view of a spacer according to an embodiment, viewed from one main surface side, in which the shaded area indicates an outer periphery region. [Figure 8] 3A to 3C are diagrams showing three examples of the shape of a main surface of a spacer according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The spacer of the present invention will be described in detail below. FIG. 1 is a perspective view of a glass spacer (hereinafter simply referred to as a spacer) 1 according to an embodiment of the present invention. FIG. 2 is a diagram for explaining the arrangement of the spacer 1 and the magnetic disk 5. FIG. FIG. 1 is a cross-sectional view of a main part illustrating an example of the structure of an HDD device in which the laser 1 is incorporated. The material of the spacer 1 includes glass, but the spacer 1 is not necessarily limited to glass. Other materials for the spacer 1 include stainless steel, titanium, aluminum, or Metal materials such as aluminum alloys, ceramics, etc. can also be used.

[0020] As shown in FIG. 2, the spacer 1 is a magnetic disk 5 and a spacer 1 stacked alternately. As shown in FIG. 3, multiple magnetic disks 5 are mounted on a rotating spindle. The magnetic disk 5 and the spacer 1 are inserted into the holder 16 with the spacer 1 between them. The clamp member 12 is fixed from above with a screw or the like to the spindle 16. As a result, the magnetic disks 5 are attached at a predetermined interval. The magnetic disk 5 on the top layer, which is supported from below by the spacer 1, is directly and locally The clamp member 12 has a protrusion 14 for pressing the magnetic disk 5. The projections 14 are arranged in a circular shape around the central axis of the handle 16. The cross section in the radial direction is an arc shape. The laminate is clamped by being pressed from the ramp member 12. is also clamped.

[0021] The spacer 1 described in the following embodiment is a spacer for mounting a magnetic disk between two magnetic disks 5. This applies to a spacer that is provided in contact with the disk 5.

[0022] As shown in FIG. 1, the spacer 1 is in an annular shape and has an outer circumferential surface 2, an inner circumferential surface 3, and The pair of main surfaces 4 are substantially parallel to each other. The peripheral surface 2 is approximately perpendicular to the pair of main surfaces 4. The surface of the spacer 1 may be appropriately chamfered (as shown in the figure). Here, "approximately parallel" means that the parallelism is, for example, 5 μm or less. Moreover, "approximately perpendicular" means, for example, 85 to 95 degrees. The inner peripheral surface 3 is the surface that comes into contact with the spindle 16 and is slightly larger than the outer diameter of the spindle 16. It is the wall surface surrounding a hole with a large inner diameter. The main surfaces 4 are the two surfaces that come into contact with the magnetic disk 5. The magnetic disk 5 is fixed in place by contact with the main surface of the magnetic disk 5 and frictional force. The magnetic disk 5 can be rotated at high speed by the rotation of the spindle 16. Magnetic information is not read or written by a magnetic head that does not read or write. can be.

[0023] The clamp member 12 that presses and fixes the magnetic disk 5 has high mechanical strength and rigidity. In terms of ease of processing, stainless steel or aluminum alloy is used. In order to reliably press and fix the topmost magnetic disk 5, a protrusion 1 extending in an arc shape is provided. 4 is arranged in a circle.

[0024] FIG. 4 shows a cross-sectional shape of a main surface 4 of the spacer 1 (a cross-section taken along the radial direction of the spacer 1). In the example shown in FIG. 4, the inclined surface (inclined region) described below is illustrated in detail. The inclination of the inclined portion (1A) is emphasized. The term "inclined portion" refers to the peripheral area of ​​at least one of the pair of main surfaces 4. At least a part of the spacer 1 is located in a radial direction from the center of the spacer 1 toward the outer circumferential surface. This refers to the portion that is inclined toward the main surface 4. At least one of the main surfaces 4 of the spacer 1 is spaced apart from the main surface 4. The height of the surface of the spacer 1 gradually decreases toward the corner between the main surface 4 and the outer peripheral surface 2 of the spacer 1. In other words, the inclined surface 1A is inclined so that the spacer 1 The thickness of the inclined surface 1A is inclined so that the thickness of the inclined surface 1A becomes thinner as ... The inclined surface 1A is inclined toward the other side of the spacer 1 as it approaches the corner. In the example shown in FIG. 4, the inclination is toward the upper main surface 4. However, the inclined surfaces 1A may be provided on both the upper and lower main surfaces 4.

[0025] The reason for providing the inclined surface 1A on the outer peripheral surface 2 side from a certain radial position of the main surface 4 is The magnetic disk 5 is pressed and fixed by the clamp member 12. This is to prevent deterioration of flatness due to warping of the clamp member 12. 13 is a cross-sectional view illustrating a fixed state of the air disk 5. FIG. When a conventional spacer 1 without an inclined surface 1A is used, the magnetic disk The disk 5 is pressed by the projection 14 and warps upward. This is due to the following mechanism. That is, in recent years, the magnetic disk 5 has become a relatively thin plate material. Therefore, the local pressure force from the tip of the arc-shaped protrusion 14 is diffused to the magnetic disk 5. As a result, the pressing force from the protrusion 14 is transmitted to the spacer 1. The portion of the main surface 4 of the spacer 1 directly below the tip of the projection 14 (the central periphery of the main surface 4) ) is locally recessed, and as a result, the shape of the main surface 4 changes from the recessed portion to the outer peripheral surface side (the main surface The outer peripheral region of the main surface 4 is deformed so that it rises upward. The magnetic disk 5 sandwiched between the spacer 1 and the clamp member 12 is oriented upward as shown by the dotted line. It is thought that the curve will rise.

[0026] In contrast, in the spacer 1 of the embodiment, as shown in FIG. The thickness of the spacer 1 is tapered toward the corner between the main surface 4 and the outer peripheral surface 2 of the spacer 1. Therefore, the main surface 4 receiving the pressing force of the protrusion 14 is inclined as shown in FIG. Even if a portion (the central region of the main surface 4) is locally recessed, the portion on the outer circumferential surface side (the main surface The outer peripheral area of ​​the surface 4) does not rise upward from the recessed portion. The depression of the main surface 4 caused by the pressing force of the protrusion 14 can be offset. In anticipation of deformation of the main surface 4 subjected to the force, the outer periphery of the protrusion 14 is The portion of the main surface 4 on the side of the surface 2 is inclined to form an inclined surface 1A so that the thickness of the spacer 1 becomes thinner. Therefore, the portion on the outer peripheral surface 2 side does not rise upward. The magnetic disk 5 does not warp upward as shown by the dotted line in FIG. In other words, the magnetic disk 5 is moved toward the corner between the main surface 4 and the outer peripheral surface 2 of the spacer 1. It is tilted away from

[0027] Fig. 6 is a cross-sectional view of a spacer having a chamfered surface between the main surface and the outer circumferential surface. FIG. 6 is a view of a spacer having an annular shape as viewed from one main surface side, and is the same as that shown in FIG. 7 is a cross-sectional view of the spacer taken along the line AA in FIG. At least a part of the outer circumferential region is provided with a groove in a radial direction from the center of the spacer toward the outer circumferential surface. The inclined region 1A (as described above, in this specification, " On the other hand, the space shown in Figure 6 The laser includes an outer peripheral surface 2, an inner peripheral surface 3, and a main surface 4 opposed to each other. There is a chamfered surface 6 between the main surface 4 and the inner peripheral surface 3 as shown in FIG. A chamfered surface 6A may be provided.

[0028] In one embodiment, the inclined region 1A is a curved surface that is convex in a direction from the inside to the outside of the spacer. By forming the inclined region 1A in such a shape, the pressing force of the protrusion 14 is reduced. The shape of the main surface 4 deformed under pressure is almost flat without bending upward or downward. The amount of clearance D (inner circumference) of the inclined region 1A before the force of the protrusion 14 is applied is From the start position S of the inclined surface 1A on the side of the surface 3 to the end position of the inclined area 1A on the side of the outer peripheral surface 2 The amount of change in position in the thickness direction. Note that the inclined area is only a part of the main surface and is not included in the chamfered surface. (D) is, for example, 2.0 μm or less. If the clearance D exceeds 2.0 μm, It may take time to manufacture the spacer 1, which may increase the production cost. The amount of clearance D is more preferably 1.5 μm or less. If the drop amount D is less than 0.1 μm, the clamped state Therefore, the effect of suppressing the deterioration of the flatness of the magnetic disk 5 in the magnetic recording medium may be reduced.

[0029] The starting position S of the inclined surface 1A is a distance from the center of the annular shape of the spacer 1 in the radial direction of the spacer 1. When the length of the main surface along the line is L (L is also called the width of the main surface of the spacer 1), At a position radially away from the edge on the outer periphery of the surface by a distance of 20% or more of the length L It is preferable that the start position S of the inclined surface 1A is halfway from the edge position on the outer circumferential surface side of the main surface. If the magnetic disks are located radially apart by less than 20% of the length L, the magnetic disks in the clamped state There is a possibility that the effect of suppressing the deterioration of the flatness of the disk 5 will be reduced. FIG. 8 illustrates an example of the shape of the main surface 4 of the spacer 1 in cross section. 8 shows three typical examples of the shape (cross-sectional view) of the outer peripheral region of the main surface 4. In these figures, the inclination of the inclined surface is emphasized, and the chamfered surface 6 is not shown. do not have. On the main surface of the spacer 1, a corner between the main surface 4 and the outer peripheral surface 2 (however, the main surface 4 and If there is a chamfered surface 6 between the main surface 4 and the outer peripheral surface 2, toward the corner between the main surface 4 and the chamfered surface 6 The height of the surface of the spacer 1 gradually decreases (or the thickness of the spacer 1 gradually decreases). In this case, the inclined surface is called a "fringed edge shape" (see Fig. 4 and Figure 8(a). The main surface of the spacer 1 has a different inclination such that the surface height decreases toward the inner peripheral surface 3. In the case where a surface exists (i.e., the cross-sectional shape of the main surface in the radial direction is an upward convex arc shape), The starting position S of the inclined surface 1A is convex upward. The position of the apex of the spacer in the thickness direction on the arc of the spacer can be determined. When there are multiple upwardly convex arc shapes on the profile of the main surface, The highest position can be set as the start position S of the inclined surface 1A. In addition, the shape of the main surface of the spacer 1 is such that, in a cross-sectional view in the radial direction, the edge on the inner circumferential surface side is When the surface roughness decreases monotonically from the surface to the edge on the outer periphery (non-linear but monotonically decreasing) Hereinafter, this will be referred to as a "substantially linear shape." See FIG. 8(c). Position S may be an edge on the inner circumferential surface side of the main surface.

[0030] The drop amount D can be measured, for example, by an optical interferometer. For example, the flatness can be measured using a NIDEK flatness tester FT-17. After acquiring the surface profile data, the radial cross-sectional profile of the spacer 1 is analyzed (i.e., Display and analyze the height data of the spacer main surface along any radial direction as a cross section) , the start position S of the inclined surface 1A and the end position S of the inclined surface 1A (the boundary between the main surface and the chamfered surface on the outer periphery) ) and calculate the difference in thickness (difference in height) This measurement was repeated every 90 degrees with the center of spacer 1 as the reference to obtain four data points. The average value of these can be used as the clearance D for one main surface. The main surface of the spacer 1 is ground or polished in the same manner as in the manufacture of the magnetic disk substrate. In this case, a double-sided simultaneous processing device is basically used, so the clearance D for each of the pair of main surfaces is It will be almost equal. In addition, the outer peripheral region of the main surface is not included in the individual radial profile data. In some cases, the position of the outer peripheral edge on the main surface is the highest. For example, the height of the edge on the outer periphery side is The minimum height on the main surface profile is calculated, and the difference between the minimum height and the minimum height on the main surface profile is calculated. By doing this, you can get the other allowances. Since the calculation can be performed in conjunction with the data, the average value of the allowance for the main surface 4 can be calculated as The inclination of the inclined surface 1A with respect to the horizontal portion of the main surface 4 can be understood clearly. The inclination angle is, for example, 0 degrees to 5 degrees or less, and the inclined surface 1A has an inclination angle of, for example, 20 degrees or more. This is different from the chamfered surface.

[0031] According to one embodiment, the thickness of the magnetic disk 5 to be mounted in the HDD together with the spacer 1 is: The thickness of the magnetic disk 5 is preferably 80% or less of the thickness of the spacer 1. It is more preferable that the thickness of the substrate 1 is 70% or less, and even more preferable that the thickness of the substrate 1 is 50% or less. As the thickness of the magnetic disk 5 becomes thinner, the pressing force of the clamp member 12 becomes smaller. Since the disk 5 penetrates and easily affects the spacer 1, the surface of the spacer 1 is subjected to a pressing force. When the spacer 1 is deformed into a concave shape, the magnetic The magnetic disk 5 follows suit and bends significantly. However, the position may shift from the specified position in the thickness direction, causing problems such as contact with the lamp. However, by using the spacer 1 of this embodiment, the above-mentioned case can be prevented. Since the recess of the spacer 1 can be offset, the warping of the magnetic disk 5 can be suitably prevented. That is, the warping of the magnetic disk 5 can be suppressed. The length is, for example, 0.5 to 3 mm, and the thickness of the magnetic disk 5 is, for example, 0.2 to 0.8 mm. The substrate material of the magnetic disk 5 is not particularly limited, but may be, for example, a glass substrate or an aluminum substrate. Among these, aluminum alloy substrates are preferred because of their relatively high rigidity. From the viewpoint of achieving a high effect of SA1, a glass substrate is more preferable.

[0032] According to one embodiment, the Young's modulus of the spacer 1 is set to be equal to or larger than that of the substrate constituting the magnetic disk 5. It is preferable that the Young's modulus is smaller than that of the clamp member 12. The pressure is transmitted to the spacer 1 without deforming or damaging the magnetic disk 5. The portion of the main surface of the spacer 1 that is subjected to the pressing force of the clamp member 12 is easily broken. As a result, it is possible to prevent the main surface of the spacer 1 from being dented. In other words, the spacer 1 receives the pressing force and changes the shape of the inclined surface 1A to a horizontal surface. The Young's modulus of the spacer 1 is, for example, 60 to 80. 200 [GPa], and the Young's modulus of the substrate constituting the magnetic disk 5 is, for example, 70 to 11 0 [GPa]. In addition, when amorphous glass is used as the material of the spacer 1, The Young's modulus of the spacer 1 is preferably set to, for example, 60 to 100 [GPa].

[0033] The material of the spacer 1 is not particularly limited. When the material is glass, aluminum Nosilicate glass, soda lime glass, soda aluminosilicate glass, aluminoboro Examples include silicate glass, boron silicate glass, quartz glass, and crystallized glass. Among these, the surface smoothness of the spacer 1 can be easily increased and it is relatively easy to process. From this point of view, amorphous glass is preferable. Aluminosilicate glass is For example, silicon dioxide (SiO2): 59 to 63 mass%, aluminum oxide (Al2O3 ): 5 to 16 mass%, lithium oxide (LiO): 2 to 10 mass%, sodium oxide (N a2O): 2-12 mass%, zirconium oxide (ZrO2): 0-5 mass% Amorphous glass can be used. Soda lime glass is, for example, SiO2: 65~75% by mass, Al2O3: 1~6% by mass, CaO: 2~7% by mass, Na2O: 5~ It is possible to use amorphous glass containing 17% by mass of ZnO and 0 to 5% by mass of ZrO2. can.

[0034] The glass material that is the basis of the spacer 1 is manufactured by the float method or down-draw method. Plate glass cut into a circular shape, molten glass formed by pressing, tube drawing Glass tubes manufactured by the method of manufacture, sliced ​​to an appropriate length, etc. The end surface (outer or inner surface) or the main surface of the thus formed circular glass may be The same grinding (including chamfering) and polishing are performed on the substrate as when manufacturing magnetic disk substrates. The method of grinding and polishing the end surface is not particularly limited, and may be, for example, Grinding or polishing is performed using a formed grinding wheel containing diamond abrasive grains of 80 to #1000. The grinding and polishing of the end surface may be performed using an abrasive brush or an abrasive pad. In addition, the grinding and polishing of the end faces is chemically performed using an etching solution containing hydrofluoric acid or hydrosilicofluoric acid. The inclined surface 1A of the main surface 4 may be formed by grinding or polishing the main surface 4, or by applying the same. For example, in the polishing process, alumina and silica can be used. A slurry containing abrasive grains and a suede-type soft polyurethane foam polishing pad are used. By using cerium abrasive, the above-mentioned amount of allowance D can be increased. By using a slurry containing 100% fluorine and a suede-type polishing pad, the peripheral area of ​​the main surface is polished upward. In addition, the concentration of the slurry, the hardness of the polishing pad, and other conditions can be changed. By changing or combining the two, you can create a flat main surface without a slope, or change the starting point of the slope. You can also adjust the S.

[0035] The dimensions of the annular spacer 1 may be changed as appropriate depending on the specifications of the HDD to be mounted. However, if it is for a nominal 3.5-inch HDD device, the outer diameter is, for example, 30 to 34 mm. The inner diameter is, for example, 25 mm, and the thickness is, for example, 0.5 to 3 mm. When a chamfer is provided on the peripheral surface or outer peripheral surface, the angle of the chamfer with respect to the main surface is, for example, 20 to 70°. The radius of the main surface is, for example, 50 to 500 μm. It may be a straight line or a curved line when viewed in a cross section in the direction. The dimensions of the magnetic disk 5 may also be changed as appropriate depending on the specifications of the HDD to be mounted. However, if it is for a nominal 3.5-inch HDD device, the outer diameter is, for example, 85 to 100 mm. The inner diameter is, for example, 25 mm, and the thickness is, for example, 0.2 to 0.8 mm.

[0036] According to one embodiment, the surface of the spacer 1 is preferably provided with a conductive film. Examples of conductive film materials include nickel alloys such as nickel phosphorus (NiP) and tin oxide. (SnO2), zinc oxide (ZnO), titanium oxide, and tin oxide doped with fluorine (FTO) Conductive oxides such as AZO, which is zinc oxide doped with aluminum oxide (Al2O3), etc. By providing a conductive film on the surface of the spacer 1 in this way, The static electricity on the magnetic disk 5 is transferred from the spacer 1 through the metallic spindle 16. It can be discharged to the outside, and can prevent foreign matter and It is possible to reduce the adsorption of fine particles. It is also possible to prevent dust generation from the surface of the base material of the spacer 1. It is also possible. The base material of the spacer 1 having the conductive film may be made of glass, ceramics, etc. It may be made of metal.

[0037] According to one embodiment, the thickness of the magnetic disk 5 to be mounted in the HDD together with the spacer 1 is: It is preferable that the thickness is 0.55 mm or less. In the case of a magnetic disk 5 having a thickness of 0.55 mm or less, The pressing force of the ramp member 12 penetrates the magnetic disk 5 and easily affects the spacer 1. Therefore, the surface of the spacer 1 is likely to deform into a concave shape around the area where the pressure is applied. Furthermore, since the magnetic disk 5 is thin, it easily conforms to the concave spacer 1. The magnetic disk 5 becomes easily bent. However, even in this case, the inclined surface 1A described above is The spacer 1 having the spacer 1 is preferable because it can suppress or even prevent the above-mentioned bending.

[0038] In an HDD device having such a spacer 1 and a magnetic disk 5, As the number of magnetic disks 5 increases, the pressing force of the clamping member 12 to fix the magnetic disks 5 increases. Therefore, in the conventional spacer without the inclined surface 1A, The more the number of magnetic disks 5 increases, the more the warping of the magnetic disks 5 increases. By using the spacer 1 having the surface 1A, the magnetic In this respect, the magnetic disk 5 is less likely to warp. In the HDD device, the spacer 1 having the inclined surface 1A functions effectively. In the HDD device equipped with the above magnetic disk, a spacer 1 having an inclined surface 1A is used. This is even more effective. In this case, the use of a spacer 1 having an inclined surface 1A is even more effective.

[0039] The main surface 4 of the spacer 1 shown in FIG. 4 has a portion where the main surface 4 and the outer peripheral surface 2 are in contact with each other. The thickness of the spacer 1 becomes thinner toward the corner between the spaces, forming an inclined surface 1A. The inner peripheral side portion is a horizontal surface with no inclination, while the inclined surface 1A extends toward the outer peripheral side. However, instead of a horizontal plane, the main surface 4 and the inner peripheral surface 3 are inclined from the starting position of the inclined surface 1A. The thickness of the spacer 1 becomes thinner toward the corner between the In this case, the start position S of the inclined surface 1A is the most upwardly protruding point.

[0040] In addition, one modification of the present invention is a hard disk drive device in which the main surface is a magnetic disk. This is a ring-shaped spacer that is provided so as to be in contact with the disk. The main surface on at least one side of the spacer has a portion of the main surface, A corner between the main surface and the outer circumferential surface of the spacer is formed. In other words, the inclined surface is inclined so that at least one of the spacers The main surface on the side of the spacer is in contact with the main surface of the spacer and the outer circumferential surface of the spacer at a part of the main surface. and a corner between the spacer and the main surface on the other side of the spacer. The "corner" here means a chamfered surface between the main surface and the outer circumferential surface. , refers to the edge between the major surface and the chamfered surface.

[0041] Further, another modification of the present invention is a hard disk drive device in which the main surface is a magnetic disk. The spacer is an annular spacer provided in contact with the disk. The main surface on the other side is a portion of the main surface of the spacer. and an inclined surface inclined so that the thickness of the spacer becomes thinner toward a corner between the outer circumferential surface. It is as follows. EXAMPLES

[0042] Using a HDD with nine magnetic disks, the amount of clearance in the outer peripheral area of ​​the main surface of the spacer was measured. D and the change in flatness (warping) of the magnetic disk (fixed on top) before and after clamping Specifically, we first investigated the relationship between the amount of data and the amount of data on the top magnetic disk from the HDD spindle. The magnetic disk and the spacer immediately below it were removed, and the flatness of the removed magnetic disk was measured. Then, any spacer for which the clearance D has been measured is placed on the spindle with the surface on which the clearance D has been measured facing up. Then, a magnetic disk whose flatness has already been measured is attached to the spindle. The disk is then clamped with a clamping member, and the flatness of the top surface of the disk is checked in this state. Anything that might interfere with the measurement (such as ramp parts) was removed from the HDD in advance. The flatness (warping) of the magnetic disk was measured using an optical disk manufactured by Phase Shift Technology. The maximum height difference on the surface of the magnetic disk was measured using a flat.

[0043] The specifications of the spacer and magnetic disk are as follows: Spacer: Amorphous glass (Young's modulus: 72 GPa), outer diameter 32 mm, The inner diameter is 25 mm, the plate thickness is 1.8 mm, and the chamfered surface has a radial length of 2 on both the inner and outer circumference. The diameter of the main surface is 50 μm, and the angle with respect to the inner and outer peripheral surfaces is 45 degrees. The width L of the main surface is 3.0 mm. By adjusting the manufacturing conditions of the spacer, the size of the drop amount D of the inclined surface can be varied to suit various spacers. We manufactured a laser scanner. Magnetic disk: A magnetic film is formed on a glass substrate. The Young's modulus of the glass substrate is 8 The pressure was 0 GPa, diameter 97 mm, inner diameter 25 mm, and plate thickness 0.5 mm.

[0044] <Drop-off amount D> Four data points were obtained at 90 degree intervals on one main surface of one spacer, and the average value was calculated. did. The sign of the allowance D is defined as follows: The main surface profile is inclined (i.e., descending) toward the other main surface as it approaches the outer periphery. shape) (i.e., in the case of the spacer of the present invention) is positive, and conversely, The value increases with increasing temperature, and the value at the outer peripheral edge is considered negative.

[0045] <Change in flatness> Basically, the flatness of the magnetic disk is greater after clamping than before clamping. In most cases, the change in flatness is the same, but the opposite is also true, so the change in flatness is shown as an absolute value. If the amount of oxidation is 4 μm or less, it can be used, and if it is 3 μm or less, it is preferably used. It is possible, and it is more preferable if it is 2.5 μm or less.

[0046] [Table 1]

[0047] As shown in the above results, by setting the drop allowance D to be greater than 0 (plus), the change in flatness is increased by 4. It was also found that the amount of clearance D can be set to 0.1 to 2.0 μm or less. It was found that the change in flatness was reduced to 3 μm or less by setting the drop amount D to 0.1 to 1 It was found that by setting the thickness at .5 μm, the change in flatness could be reduced to 2.5 μm or less.

[0048] The spacer and the hard disk drive device of the present invention have been described in detail above. The present invention is not limited to the above-mentioned embodiments and examples, and may be modified without departing from the spirit and scope of the present invention. Of course, various improvements and modifications may be made. [Explanation of symbols]

[0049] 1 Glass Spacer 1A Slope 2 Outer surface 3 Inner surface 4 Main surface 5. Magnetic Disk 10. Hard disk drive device 12 Clamping member 14 protrusions 16 Spindle 18 Rotational Axis

Claims

1. A hard disk drive device, a plurality of magnetic disks; and an annular spacer provided in the hard disk drive device such that a main surface of the spacer is in contact with any one of the magnetic disks; the spacer has a pair of main surfaces, an inner peripheral surface, and an outer peripheral surface, and a chamfered surface is provided between each of the pair of main surfaces and the outer peripheral surface; at least one of the pair of main surfaces has an inclined region inclined toward the other main surface in a radial direction from a center of the spacer toward an outer circumferential surface, the inclined region being in a range of the main surface and at least a part of an outer circumferential region, the substrate of the magnetic disk is made of an aluminum alloy; The thickness of the magnetic disk is 0.55 mm or less. Hard disk drive device.

2. 2. The hard disk drive device according to claim 1, wherein the amount of clearance in the inclined region of the spacer that is inclined toward the other main surface side is 0.1 to 2 μm.

3. A hard disk drive device, a plurality of magnetic disks; and an annular spacer provided in the hard disk drive device such that a main surface of the spacer is in contact with any one of the magnetic disks; the spacer has a pair of main surfaces, an inner peripheral surface, and an outer peripheral surface, and a chamfered surface is provided between each of the pair of main surfaces and the outer peripheral surface; at least one of the pair of main surfaces has a portion in at least a part of an outer circumferential region within the range of the main surface, the portion having an upwardly convex arc shape in a cross section in a radial direction from a center of the spacer toward an outer circumferential surface thereof, the substrate of the magnetic disk is made of an aluminum alloy; The thickness of the magnetic disk is 0.55 mm or less. Hard disk drive device.

4. 4. The hard disk drive device according to claim 3, wherein in a cross-sectional shape of the main surface, a difference in height in the thickness direction of the spacer between a vertex position in the thickness direction of the spacer on the upwardly convex arc and an edge on the outer circumferential surface side of the main surface is 0.1 to 2 μm.

5. 5. The hard disk drive device according to claim 1, wherein the number of said magnetic disks is ten or more.

6. 6. The hard disk drive device according to claim 5, wherein the number of said magnetic disks is eleven or more.

7. 7. The hard disk drive device according to claim 1, wherein a material of the spacer includes aluminum or an aluminum alloy.

8. 8. The hard disk drive device according to claim 1, wherein the Young's modulus of the spacer is smaller than the Young's modulus of a substrate that constitutes the magnetic disk.

9. A hard disk drive device, a plurality of magnetic disks; and an annular spacer provided in the hard disk drive device such that a main surface of the spacer is in contact with any one of the magnetic disks; the spacer has a pair of main surfaces, an inner peripheral surface, and an outer peripheral surface, and a chamfered surface is provided between each of the pair of main surfaces and the outer peripheral surface; at least one of the pair of main surfaces has an inclined region inclined toward the other main surface in a radial direction from a center of the spacer toward an outer circumferential surface, the inclined region being in a range of the main surface and at least a part of an outer circumferential region, the substrate of the magnetic disk is made of glass; The thickness of the magnetic disk is 0.55 mm or less, The material of the spacer includes titanium or stainless steel; The plurality of magnetic disks is 11 or more. Hard disk drive device.

10. 10. The hard disk drive device according to claim 9, wherein the clearance of the inclined region of the spacer that is inclined toward the other main surface side is 0.1 to 2 μm.

11. A hard disk drive device, a plurality of magnetic disks; and an annular spacer provided in the hard disk drive device such that a main surface of the spacer is in contact with any one of the magnetic disks; the spacer has a pair of main surfaces, an inner peripheral surface, and an outer peripheral surface, and a chamfered surface is provided between each of the pair of main surfaces and the outer peripheral surface; at least one of the pair of main surfaces has a portion in at least a part of an outer circumferential region within the range of the main surface, the portion having an upwardly convex arc shape in a cross section in a radial direction from a center of the spacer toward an outer circumferential surface thereof, the substrate of the magnetic disk is made of glass; The thickness of the magnetic disk is 0.55 mm or less, The material of the spacer includes titanium or stainless steel; The plurality of magnetic disks is 11 or more. Hard disk drive device.

12. 12. The hard disk drive device according to claim 11, wherein in a cross-sectional shape of the main surface, a difference in height in the thickness direction of the spacer between a vertex position in the thickness direction of the spacer on the upwardly convex arc and an edge on the outer circumferential surface side of the main surface is 0.1 to 2 μm.

13. 13. The hard disk drive device according to claim 1, wherein the spacer has a conductive film on a surface thereof.

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