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 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) is used.

[0003] The HDD device has magnetic disks separated from each other by a magnetic disk drive. A circular spacer is provided to hold the magnetic disk in place. The magnetic disks are spaced apart at precise positions so that they do not come into contact with each other. It works. In an HDD device, 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 spacer, and then clamped. The stack is pressed from one side with a clamping member, and the magnetic disk and The spacer is fixed.

[0004] For example, the average surface roughness of the portion in contact with the substrate for information recording medium is 0.001 to 0.005 μ 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 an 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 clamp member was significantly deteriorated. Deterioration of flatness is undesirable because it makes the magnetic disk more susceptible to fluttering when rotating at high speed. In addition, contact between the ramp member, which is the escape location for the magnetic head, and the magnetic disk occurs. This is not desirable as it makes the material more susceptible to corrosion.

[0007] Therefore, the present invention is to prevent 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 size 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 recession amount of the inclined region inclined toward the other main surface is preferably 0.1 to 2 μm. It's nice.

[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 the substrate constituting the magnetic disk; It is preferable.

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

[0014] The thickness of the magnetic disk is preferably 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 ten or more magnetic disks and the spacer. The substrate of the magnetic disk is preferably made of glass. . [Effects of the Invention]

[0017] The above-mentioned spacer prevents the magnetic disk from being flat when clamped. This can suppress the degradation. [Brief explanation 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; [Figure 2] 1A and 1B are diagrams illustrating the arrangement of a spacer and a magnetic disk according to an embodiment. [Figure 3]1 is a cross-sectional view of a main part illustrating an example of the structure of an HDD device into which a spacer according to an embodiment is incorporated. [Figure 4] 3A and 3B are diagrams illustrating in detail the shape of the main surfaces of the spacer according to the embodiment. [Figure 5] 10A and 10B 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 represents the outer peripheral region. [Figure 8] 3A to 3C are diagrams showing three examples of the shape of the main surface of a spacer according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] The spacer of the present invention will be described in detail below. FIG. 1 is a perspective view of an exterior of a glass spacer (hereinafter simply referred to as a spacer) 1 according to an embodiment. FIG. 2 is a diagram illustrating the arrangement of the spacer 1 and the magnetic disk 5. 1 is a cross-sectional view of a main part illustrating an example of the structure of an HDD device into 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 Metallic materials such as aluminum alloys, ceramics, etc. may also be used.

[0020] As shown in FIG. 2, the spacer 1 is made up of magnetic disks 5 and spacers 1 stacked alternately. As shown in FIG. 3, the magnetic disks 5 are mounted on a rotating spindle. The magnetic disk 5 and the spacer 1 are inserted into the drum 16 with the spacer 1 sandwiched therebetween. The clamp member 12 is pressed from above by a screw or the like and fixed to the spindle 16. By doing so, the magnetic disks 5 are attached at predetermined intervals. 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 projection 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 entire laminated body is clamped by being pressed from the ramp member 12. is also clamped.

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

[0022] As shown in FIG. 1, the spacer 1 has an annular shape and includes an outer peripheral surface 2, an inner peripheral surface 3, and a 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 have chamfered surfaces (as shown in the figure) as needed. Here, "substantially parallel" means that the parallelism is, for example, 5 μm or less. Furthermore, "substantially 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 large diameter hole. The main surfaces 4 of the spacer 1 are the two surfaces that come into contact with the magnetic disk 5. The magnetic disk 5 is fixed by the frictional force when it comes into contact with the main surface of the disk 5. 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. Stainless steel or aluminum alloy is used because of its ease of processing. In addition, in order to reliably press and fix the uppermost magnetic disk 5, a projection 1 extending in an arc shape is provided. 4 is arranged in a circle.

[0024] FIG. 4 shows a cross-sectional shape of the main surface 4 of the spacer 1 (a cross-section taken along the radial direction of the spacer 1). 4 is a diagram for explaining in detail the inclined surface (inclined area) described below. The inclination of the inclined surface (or inclined portion) 1A is shown in an exaggerated manner. The term "inclined portion" refers to the portion of the outer circumferential region of at least one of the pair of main surfaces 4. At least a part of the spacer 1 is 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. The main surface 4 on at least one side of the spacer 1 has a spacer 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 inclined surface 1A is inclined so that the thickness of the inclined surface 1A becomes thinner as the inclined surface 1A moves away from the magnetic disk 5. The inclined surface 1A is inclined in such a manner that the other side of the spacer 1 becomes In the example shown in FIG. 4, the upper main surface 4 is inclined. 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 from a certain radial position on the main surface 4 to the outer peripheral surface 2 in this way is , the magnetic disk 5 in a state where it is pressed and fixed by the clamp member 12 This is to prevent deterioration of flatness due to warping of the clamping member 12. 10 is a cross-sectional view illustrating the fixed state of the air disc 5. FIG. When a conventional spacer 1 without an inclined surface 1A is used, the magnetic disk The disk 5 is pressed by the protrusion 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 received from the tip of the arc-shaped protrusion 14 is diffused to the magnetic disk 5. As a result, the pressure 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 protrusion 14 (the central circumferential portion 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 (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 positioned 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. 4, a part of the main surface 4 is The thickness of the spacer 1 is reduced toward the corner between the main surface 4 and the outer peripheral surface 2 of the spacer 1. Therefore, the main surface 4 that receives the pressing force of the protrusion 14 is inclined as shown in FIG. Even if a portion (an intermediate region of the main surface 4) is locally recessed, the portion on the outer peripheral surface side (the main surface The outer peripheral area of ​​the surface 4 does not rise upward from the recessed portion. In other words, 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 an inclined surface 1A inclined so that the thickness of the spacer 1 becomes thinner. Therefore, the portion on the outer peripheral surface 2 side does not bulge 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. 6 is a view of a ring-shaped spacer as seen from one main surface side, and FIG. 7 is a cross-sectional view of the spacer taken along the line AA. In FIG. 7, the shaded area indicates the outer peripheral region of the main surface. In at least a part of the outer circumferential region, in a radial direction from the center of the spacer toward the outer circumferential surface side, The inclined region 1A (as described above, in this specification, " On the other hand, the space shown in Figure 6 The laser has an outer peripheral surface 2, an inner peripheral surface 3, and two opposing main surfaces 4. As shown in FIG. 6, there is a chamfered surface 6 between the main surface 4 and the inner peripheral surface 3. A chamfered surface 6A may be present.

[0028] In one embodiment, the inclined region 1A is a curved surface that is convex 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 can be 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 receiving the force of the protrusion 14 can be maintained flat. 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. However, the inclined area is only a part of the main surface and is not included in the chamfered surface. The clearance 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 production costs. The amount of clearance D is more preferably 1.5 μm or less. If the clearance 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 process may be reduced.

[0029] The starting position S of the inclined surface 1A is the distance from the center of the annular shape of the spacer 1 to 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 at a distance of 20% or more of the length L in the radial direction from the edge on the outer peripheral surface It is preferable that the starting position S of the inclined surface 1A is halfway from the position of the edge on the outer peripheral surface side of the main surface. If the magnetic discs are located at radially spaced positions less than 20% of the length L, There is a possibility that the effect of suppressing the deterioration of the flatness of the disk 5 will be reduced. 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 both 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, the chamfered surface 6 is The height of the surface of the spacer 1 gradually decreases (or the thickness of the spacer 1 gradually decreases). The case where the surface is inclined so that the edge of the wall is inclined is called a "rounded edge shape" (see Figure 1). 4 and Figure 8(a). On the main surface of the spacer 1, another inclination is provided so that the surface height decreases toward the inner peripheral surface 3 side. When a surface exists (i.e., when the cross section shape in the radial direction of the main surface is an upward convex arc shape, The starting position S of the inclined surface 1A is an upward convex shape. The position of the vertex 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 section in the radial direction, the edge on the inner circumferential surface side is When the temperature decreases monotonically from the surface to the edge on the outer periphery (when the temperature decreases non-linearly but monotonically) This is hereinafter referred to as a "substantially linear shape." See FIG. 8(c). Position S can be the edge on the inner circumferential surface side of the main surface.

[0030] The drop amount D can be measured by, for example, an optical interferometer. For example, it can be measured using a NIDEK flatness tester FT-17. After acquiring the surface shape data, the analysis of the radial cross-sectional shape of the spacer 1 (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 the thickness direction (difference in each 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 manufacturing of the magnetic disk substrate. In this case, a simultaneous double-sided processing device is basically used, so the clearance D for each of the pair of main surfaces is 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, if the height of the outer edge is The difference between the height and the lowest height on the main surface profile is calculated. By doing this, other allowance amounts can be Since the calculation can be performed in conjunction with the data, the average value of the amount of allowance for the main surface 4 can be calculated as The inclination of the inclined surface 1A relative to the horizontal portion of the main surface 4 can be clearly understood. The inclination angle is, for example, 0 to 5 degrees, and the inclined surface 1A has an inclination angle of, for example, 20 degrees or more. This is different from a chamfered surface.

[0031] According to one embodiment, the thickness of the magnetic disk 5 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 is 70% or less of the thickness of the substrate 1, and even more preferable that the thickness 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 pressure. When the spacer 1 is deformed into a concave shape, the magnetic The magnetic disk 5 follows suit and bends significantly. However, the part may deviate from its intended position in the thickness direction, causing problems such as contact with the lamp. However, by using the spacer 1 of this embodiment, the spacer 1 can be prevented from moving in the above-mentioned case. Since the recess of the spacer 1 can be offset, the deflection of the magnetic disk 5 can be suitably prevented. That is, it is possible to suppress the warping of the magnetic disk 5. The thickness of the magnetic disk 5 is, for example, 0.2 to 0.8 mm. There is no particular limitation on the substrate material of the magnetic disk 5, but it is possible to use, for example, a glass substrate or an aluminum substrate. Among these, aluminum alloy substrates can be used because of their relatively high rigidity. From the viewpoint of achieving a high effect of SA1, a glass substrate is more suitable.

[0032] According to one embodiment, the Young's modulus of the spacer 1 is set to be equal to or greater than that of the substrate constituting the magnetic disk 5. This makes it possible to prevent local pressure from the clamping 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 clamping 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 turns the shape of the inclined surface 1A into a horizontal surface. The Young's modulus of the spacer 1 is, for example, 60 to 100 mm. 200 [GPa], and the Young's modulus of the substrate constituting the magnetic disk 5 is, for example, 70 to 11 0 [GPa]. 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 glass is used as the material, aluminum is 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. In this respect, 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 to 12 mass%, zirconium oxide (ZrO2): 0 to 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 forms the spacer 1 is manufactured by the float method or down-draw method. Plate glass cut into a ring shape, molten glass formed by pressing, tube drawing Glass tubes manufactured by the method of slicing 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 carried out as when manufacturing magnetic disk substrates. The method for grinding and polishing the end surface is not particularly limited, and can be, for example, Grinding or polishing with a formed grinding wheel containing 80 to #1000 diamond abrasive grains The grinding and polishing of the end surface may be performed using an abrasive brush or abrasive pad. Furthermore, grinding and polishing of the end faces is performed chemically 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 these methods. For example, in the polishing process, alumina and silica can be used. Abrasive grain slurry and a suede-type soft polyurethane foam polishing pad are used. By using this, the above-mentioned removal amount D can be increased. By using a slurry containing fluorine and a suede-type polishing pad, the peripheral area of ​​the main surface is polished upward. Furthermore, the concentration of the slurry, the hardness of the polishing pad, and other conditions can be changed. By changing or combining them, you can create a flat main surface without a slope, or change the starting position of the slope. You can also adjust the S.

[0035] The dimensions of the annular spacer 1 can be changed as needed depending on the specifications of the HDD to be installed. 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 chamfered surface is provided on the peripheral surface side or the outer peripheral surface side, the angle of the chamfered surface relative to the main surface is, for example, 20 to 70°. The radius of the main surface is, for example, 50 to 500 μm. The cross section in the direction may be a straight line or a curve. The dimensions of the magnetic disk 5 may also be changed as appropriate depending on the specifications of the HDD to be installed. 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), By providing a conductive film on the surface of the spacer 1 in this way, The static electricity charged on the magnetic disk 5 is transferred from the spacer 1 through the metal spindle 16. It can be discharged to the outside, and foreign matter caused by static electricity charged on the magnetic disk 5 inside the HDD device It is possible to reduce the adsorption of fine particles and prevent dust generation from the surface of the base material of the spacer 1. You can also do this. The substrate of the spacer 1 having the conductive film may be made of glass, ceramics, or It may also be made of metal.

[0037] According to one embodiment, the thickness of the magnetic disk 5 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 pressure from 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 is prone to bending. However, even in this case, the inclined surface 1A described above is The spacer 1 having such a structure is suitable because it can suppress or even prevent the above-mentioned bending.

[0038] In an HDD device equipped with such a spacer 1 and a magnetic disk 5, the magnetic disk 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 warpage of the magnetic disks 5 increases. By using the spacer 1 having the surface 1A, the magnetic In this respect, the magnetic disks 5 are 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 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 two, forming an inclined surface 1A. The inner peripheral surface is a horizontal surface with no inclination, while the inclined surface 1A extends toward the outer peripheral surface. 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] One modification of the present invention is a hard disk drive device in which the main surface is a magnetic disk. It is a ring-shaped spacer that is provided so as to come into contact with the disk. The main surface on at least one side of the spacer has a portion of the main surface, A corner portion between the main surface and the outer circumferential surface of the spacer is formed, and the corner portion is separated from the magnetic disk. In other words, at least one of the spacers has an inclined surface inclined so as to 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. Here, the "corner" refers to a chamfered surface between the main surface and the outer peripheral surface. , refers to the edge between the main surface and the chamfered surface.

[0041] Furthermore, 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 the main surface of the spacer in a part of the main surface. and an inclined surface inclined so that the thickness of the spacer becomes thinner toward the corner between the outer circumferential surface. It is as follows. [Example]

[0042] Using an 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 (warpage) of the magnetic disk (fixed on top) before and after clamping Specifically, we first investigated the relationship between the amount of data and the magnetic disk on the top of 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 whose clearance D has been measured is placed on the spindle with the surface on which the clearance D has been measured facing upward. Then, a magnetic disk whose flatness has been measured in advance is attached to the spindle. The magnetic disk is then clamped with a clamping member, and the flatness of the top surface of the magnetic disk is checked in this state. Anything that might interfere with the measurement (such as ramp components) was removed from the HDD beforehand. The flatness (warpage) of the magnetic disk was measured using an optical disc 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 thickness is 1.8 mm, and the chamfered surface has a radial length of 2 mm on both the inner and outer sides. The diameter of the main surface was 50 μm, and the angle with respect to the inner and outer peripheral surfaces was 45 degrees. The width L of the main surface was 3.0 mm. By adjusting the manufacturing conditions of the spacer, the size of the clearance D of the inclined surface can be adjusted to suit various spaces. We manufactured a laser. 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] <Dropout 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 loss 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 as the temperature increases, and the value at the outer edge is considered negative.

[0045] <Change in flatness> Basically, the flatness of the magnetic disk is greater after clamping than before clamping. However, the opposite is true in some cases, so the amount of 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 clearance amount D to be greater than 0 (plus), the change in flatness is increased by 4. It was also found that by setting the clearance D to 0.1 to 2.0 μm, It was found that the amount of change in flatness could be reduced to 3 μm or less. It was found that by setting the thickness to 0.5 μm, the amount of 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-described embodiments and examples, and any modifications and variations are possible within the 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 spindles 18 Rotation axis

Claims

1. A hard disk drive device, a plurality of magnetic disks; and an annular spacer provided in the hard disk drive device so that a main surface of the spacer is in contact with 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 the center of the spacer toward the outer circumferential surface, in at least a part of an outer circumferential region within the range of the main surface, 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 inclined toward the other main surface 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 so that a main surface of the spacer is in contact with 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 cross section in a radial direction from a center of the spacer toward the outer circumferential surface, 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 the difference in height in the thickness direction of the spacer between the vertex position of the spacer in the thickness direction on the upwardly convex arc and the edge on the outer peripheral surface side of the main surface in the cross-sectional shape 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 plurality of magnetic disks is 10 or more.

6. 6. The hard disk drive device according to claim 5, wherein the number of said plurality of magnetic disks is 11 or more.

7. 7. The hard disk drive device according to claim 1, wherein the 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 so that a main surface of the spacer is in contact with 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 the center of the spacer toward the outer circumferential surface, in at least a part of an outer circumferential region within the range of the main surface, the substrate of the magnetic disk is made of glass; The thickness of the magnetic disk is 0.55 mm or less, the spacer is made of a material including 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 amount of clearance in the inclined region of the spacer inclined toward the other main surface 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 so that a main surface of the spacer is in contact with 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 cross section in a radial direction from a center of the spacer toward the outer circumferential surface, the substrate of the magnetic disk is made of glass; The thickness of the magnetic disk is 0.55 mm or less, the spacer is made of a material including titanium or stainless steel; the plurality of magnetic disks is 11 or more; Hard disk drive device.

12. 12. The hard disk drive device of claim 11, wherein the difference in height in the thickness direction of the spacer between the vertex position of the spacer in the thickness direction on the upwardly convex arc and the edge on the outer peripheral surface side of the main surface in the cross-sectional shape 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 its surface.

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