Spacer and hard disk drive device

Abstract

The present invention provides a spacer and a hard disk drive device that suppress the deterioration of flatness in a magnetic disk when it is clamped and fixed. [Solution] An annular spacer 1 is provided inside a hard disk drive device such that its main surface is in contact with a magnetic disk, the spacer having a pair of main surfaces 4, an inner circumferential surface 3, and an outer circumferential surface 2, with a chamfered surface between each of the pair of main surfaces and the outer circumferential surface, and on at least one of the pair of main surfaces, there is an inclined region 1A that is inclined toward the other main surface in the radial direction from the center of the spacer toward the outer circumferential surface, within the range of the main surface and at least a part of the outer circumferential region, and the material of the spacer includes glass.

Description

Technical Field

[0001] The present invention relates to an annular spacer provided so as to contact a magnetic disk in a hard disk drive device and a hard disk drive device.

Background Art

[0002] With the recent prosperity of cloud computing, many hard disk drive devices (hereinafter also referred to as HDD devices) are used in cloud-oriented data centers for increasing the storage capacity.

[0003] In an HDD device, an annular spacer is provided between magnetic disks in the HDD device to hold the magnetic disks apart from each other. This spacer functions so that the magnetic disks do not contact each other and the magnetic disks are accurately spaced apart at predetermined positions. In an HDD device, a spindle is passed through the inner holes of a magnetic disk and a spacer with the spacer sandwiched between a plurality of magnetic disks to form a laminate of the magnetic disk and the spacer, and the laminate is pressed from one side by a clamp member so that the magnetic disk and the spacer are fixed.

[0004] For example, a glass spacer having an average surface roughness of 0.001 to 0.005 μm at a portion contacting a substrate for an information recording medium is known (Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] In an HDD device where the magnetic disk is fixed using the spacers described above, It was found that the flatness of the main surface of the magnetic disk closest to the component deteriorated significantly. A decrease in flatness is undesirable because it makes the magnetic disk more prone to fluttering when it rotates at high speeds. It is not good. Also, contact between the lamp component, which is the retraction point for the magnetic head, and the magnetic disk occurs. This is undesirable because it makes things easier.

[0007] Therefore, the present invention suppresses the deterioration of flatness in the magnetic disk when it is clamped and fixed. The objective is to provide a spacer for use in hard disk drive devices. [Means for solving the problem]

[0008] One aspect of the present invention is a hard disk drive in which the main surface is in contact with the magnetic disk. It is a ring-shaped spacer provided for this purpose. The spacer has a pair of main surfaces, an inner circumferential surface, and an outer circumferential surface, and the pair of main surfaces There is a chamfered surface between each of these and the aforementioned outer surface. At least a portion of the peripheral region of at least one of the pair of main surfaces is A sloping region inclined toward the other main surface in the radial direction from the center of the spacer toward the outer surface. It is characterized by having a region.

[0009] The amount of drop in the inclined region on the other main surface side is preferably 0.1 to 2 μm. It's nice.

[0010] The inclined region is a curved surface that is convex in the 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] It is preferable that the material of the spacer contains glass.

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

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

[0014] It is preferable that the thickness of the magnetic disk is 0.55 mm or less.

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

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

Advantages of the Invention

[0017] According to the above-described spacer, deterioration of flatness in the magnetic disk in the clamped and fixed state can be suppressed.

Brief Description of the Drawings

[0018] [Figure 1] It is an external perspective view of a spacer for a magnetic disk according to an embodiment. [Figure 2] It is a diagram for explaining the arrangement of a spacer and a magnetic disk according to an embodiment. [Figure 3]This is a cross-sectional view of a key part illustrating an example of the structure of an HDD device into which a spacer of one embodiment is incorporated. [Figure 4] This figure illustrates in detail the shape of the main surface of a spacer according to one embodiment. [Figure 5] This diagram illustrates how the magnetic disk is secured by the top clamp inside the HDD device. [Figure 6] Figure 7 is a cross-sectional view AA of a spacer according to one embodiment. [Figure 7] This is a view of a spacer of one embodiment, seen from the main surface side. In the figure, the shaded area represents the outer periphery. [Figure 8] This figure shows three examples of the main surface shape of the spacer in the embodiment. [Modes for carrying out the invention]

[0019] The spacer of the present invention will be described in detail below. Figure 1 is an external perspective view of a glass spacer (hereinafter simply referred to as "spacer") 1 according to one embodiment. Figure 2 is a diagram illustrating the arrangement of spacer 1 and magnetic disk 5. Figure 3 is a diagram illustrating the arrangement of spacer 1 and magnetic disk 5. This is a cross-sectional view of a key part illustrating an example of the structure of an HDD device into which -S 1 is incorporated. The material of spacer 1 may include glass, but spacer 1 is not necessarily limited to glass. It will not be done. Other materials for Spacer 1 include stainless steel, titanium, aluminum, or Metal materials such as aluminum alloys, or ceramics, can also be used.

[0020] As shown in Figure 2, the spacer 1 is formed by stacking the magnetic disk 5 and the spacer 1 alternately. It is incorporated into a DD device. As shown in Figure 3, multiple magnetic disks 5 rotate on a speedometer. The spacer 1 is inserted into the handle 16, and the stack of magnetic disk 5 and spacer 1 It is pressed from above by a clamp member 12, which is fixed with screws or the like, and fixed to the spindle 16. As a result, the magnetic disks 5 are mounted at predetermined intervals. Clamp member 12 This directly and locally transmits the uppermost magnetic disk 5, which is supported from below by the spacer 1. It applies pressure to the target. The clamp member 12 has projections 14 for pressing the magnetic disk 5. It is arranged in a circular pattern around the central axis of the handle 16. The tip of the projection 14 is half of the clamp member. The cross-section in the radial direction is arc-shaped. In this way, the uppermost magnetic disk 5 is The lamp member 12 is pressed and clamped. And the entire laminate is subjected to this pressing force. It will also be clamped.

[0021] Furthermore, the spacer 1 described in the following embodiment is a magnetic disk between two magnetic disks 5. This refers to a spacer that is provided in contact with the screw 5.

[0022] As shown in Figure 1, the spacer 1 has an annular shape, with an outer circumferential surface 2, an inner circumferential surface 3, and It has two opposing main surfaces 4. The pair of main surfaces are substantially parallel. Also, the inner circumferential surface 3 and the outer surface The circumferential surface 2 is substantially perpendicular to the pair of main surfaces 4. The surface of the spacer 1 has a chamfered surface (as shown in the figure) as appropriate. (It may be provided without) Here, "approximately parallel" means, for example, that the degree of parallelism is 5 μm or less. Also, "approximately perpendicular" means, for example, an angle of 85 to 95 degrees. The inner circumferential surface 3 is the surface that contacts the spindle 16, and is slightly smaller than the outer diameter of the spindle 16. It is the wall surrounding a hole with a large inner diameter. The main surface 4 consists of two surfaces that are in contact with the magnetic disk 5. The main surface 4 of the spacer 1 is the magnetic disk The main surface of the disk 5 is in contact with the magnetic disk 5 and fixed by frictional force. The magnetic disk 5 can be rotated at high speed by the rotation of the spindle 16, as shown in the figure. Magnetic information is read or written by a magnetic head that does not read or write. It can be done.

[0023] The clamp member 12 that presses and secures the magnetic disk 5 has high mechanical strength and rigidity. Stainless steel or aluminum alloys are used because they are easy to process. Furthermore, in order to securely press and fix the uppermost magnetic disk 5, an arc-shaped projection 1 is provided. Number 4 is arranged in a circular pattern.

[0024] Figure 4 shows the cross-sectional shape of the main surface 4 of the spacer 1 (a cross-section cut along the radial direction of the spacer 1). This figure provides a detailed explanation of the surface shape. In the example shown in Figure 4, the inclined surface (inclined region) described below is shown. Alternatively, the inclination of the inclined part (1A) is emphasized. Here, the inclined surface, the inclined region, The term "inclined portion" refers to the outer peripheral region of at least one of the pair of main surfaces 4. At least in some cases, in the radial direction from the center of spacer 1 toward the outer surface, other This refers to the part of the main surface that slopes toward the side of the main surface 4. The main surface 4 on at least one side of the spacer 1 is, in part of the main surface 4, space The surface height of spacer 1 gradually decreases towards the corner between the main surface 4 and the outer surface 2 of spacer 1. The inclined surface 1A is such that it becomes sloping. In other words, the inclined surface 1A is spacer 1 It is sloped so that its thickness becomes thinner. Also, the inclined surface 1A is separated from the magnetic disk 5. It is inclined in such a way. Also, the inclined surface 1A is on the other side of spacer 1 as it approaches the corner. It is inclined to approach the main surface 4 located there. In the example shown in Figure 4, it is inclined towards the upper main surface 4. Although a surface 1A is provided, the inclined surface 1A may also be provided on the main surfaces 4 on both the upper and lower sides.

[0025] In this way, the inclined surface 1A is provided on the side of the outer peripheral surface 2 from a radial position where the main surface 4 is located. , the magnetic disk 5 in a state where it is pressed and fixed by the clamp member 12 This is to suppress the deterioration of flatness due to the warping of part 5. Figure 5 shows the magnetic clamp member 12. This diagram shows a cross-sectional view illustrating the fixed state of the gas disk 5. When using a conventional spacer 1 without an inclined surface 1A, as shown by the dotted line in Figure 5, the magnetic field The screw 5 is pressed by the projection 14 and bends upward. This is due to the following mechanism. This is thought to be caused by the fact that in recent years, magnetic disks 5 have become relatively thin. Therefore, the localized pressing force received from the arc-shaped tip of the projection 14 is diffused onto the magnetic disk 5. The pressing force from the projection 14 is transmitted to the spacer 1. As a result, the pressing force from the projection 14 In response, the portion of the main surface 4 of the spacer 1 directly below the tip of the projection 14 (the middle circumference portion of the main surface 4) ) is locally indented, and as a result, the shape of the main surface 4 is such that the part on the outer surface side (main surface) is indented. The outer peripheral region of surface 4 deforms in such a way that it bulges upward. Following the same pattern, the magnetic disk 5, sandwiched between spacer 1 and clamp member 12, moves upward as shown by the dotted line. It is thought that it will curve upwards.

[0026] In contrast, in the spacer 1 of the embodiment, as shown in Figure 4, a part of the main surface 4 is The thickness of spacer 1 decreases towards the corner between the main surface 4 and the outer surface 2 of paser 1. The inclined surface 1A is such that the main surface 4 that receives the pressing force of the projection 14 Even if a portion (the middle peripheral region of the main surface 4) is locally concave, the portion on the outer peripheral side (main surface) will not be affected. The outer peripheral region of surface 4 does not rise upward from the recessed area. In other words, The indentation of the main surface 4 caused by the pressing force of projection 14 can be offset. In other words, the projection 14 Anticipating that the main surface 4 will deform when subjected to force, the outer circumference of the projection 14 is positioned relative to the force-receiving portion. The main surface 4 on the side of surface 2 is made into an inclined surface 1A such that the thickness of the spacer 1 becomes thinner. Therefore, the side portion of the outer surface 2 does not bulge upwards. The magnetic disk 5 does not curve upward as shown by the dotted line in Figure 5. The inclined surface 1A is In other words, the magnetic disk 5 is directed toward the corner between the main surface 4 and the outer peripheral surface 2 of the spacer 1. It slopes away from it.

[0027] Figure 6 is a cross-sectional view of a spacer with a chamfered surface between the main surface and the outer surface. Figure 7 is Figure 6 shows a circular spacer as viewed from one of its main surfaces, and Figure 7 shows the same configuration. This is a cross-sectional view of the spacer AA. In Figure 7, the shaded area is the outer peripheral region of the main surface. In at least a portion of the outer peripheral region, in the radial direction from the center of the spacer toward the outer peripheral surface The inclined region 1A on the other main surface side (as described above, in this specification, It is sometimes called an "inclined surface" or "inclined section.") On the other hand, the space shown in Figure 6 The filter comprises an outer circumferential surface 2, an inner circumferential surface 3, and two opposing main surfaces 4, with the main surface 4 and the outer circumferential surface 2 There is a chamfered surface 6 between it and the main surface 4 and the inner circumferential surface 3. A handle surface 6A is also acceptable.

[0028] In one embodiment, the inclined region 1A is a curved surface that is convex in the direction from the inside to the outside of the spacer. It is preferable that the inclined region 1A is shaped in this way, so that the projection 14 is pressed The shape of the main surface 4, which is deformed under pressure, is almost water-like without curving upward or downward. It can be kept flat. The amount of drop D (inner circumference) of the inclined region 1A before it is subjected to the force of projection 14. From the starting position S of the inclined surface 1A on the side of surface 3 to the ending position of the inclined region 1A on the side of outer peripheral surface 2 The amount of change in position in the thickness direction. However, the inclined region is only a part of the main surface and is not included in the chamfered surface. It is rare.) For example, it is 2.0 μm or less. If the amount of fallout D exceeds 2.0 μm, Manufacturing spacer 1 takes time and could increase production costs. From a similar perspective, The amount of material removed D is more preferably 1.5 μm or less. Also, the amount of material removed D is 0.1 It is preferable that it is μm or larger. If the drop amount D is less than 0.1 μm, the clamp fixed state The effect of suppressing the deterioration of the flatness of the magnetic disk 5 may be reduced.

[0029] The starting position S of the inclined surface 1A is in the radial direction of the spacer 1, from the center of the annular shape 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 spacer 1), the main At a position radially separated from the edge on the outer periphery of the surface by a distance of 20% or more of length L. It is preferable that the starting position S of the inclined surface 1A is half the position of the edge on the outer circumferential side of the main surface. When located at a distance of less than 20% of the length L in the radial direction, the magnetic field in the clamped state The effect of suppressing the deterioration of disc 5's flatness may be reduced. Figure 8 illustrates an example of the shape of the main surface 4 of spacer 1 in a cross-sectional view. Section 8 shows three representative examples of the shape (cross-sectional view) of the outer peripheral region of the main surface 4. In this figure as well, the inclination of the inclined surface is exaggerated, and the chamfered surface 6 is not shown. do not have. On the main surface of spacer 1, the 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 outer peripheral surface 2, then towards the corner between the main surface 4 and the chamfered surface 6. The height of the surface of spacer 1 gradually decreases (or the thickness of spacer 1 gradually decreases) When the surface is sloped in such a way as shown in the diagram, it will be called a "sloping edge shape" (Figure See Figures 4 and 8(a). On the main surface of spacer 1, there is another slope such that the surface height decreases toward the inner circumferential surface 3. If a surface exists (i.e., the radial cross-sectional shape of the main surface is an upward-convex arc). Below, this is called an arc shape. See Figure 8(b). The starting position S of the inclined surface 1A is convex upwards. This can be the vertex position in the thickness direction of the spacer on the arc. If multiple upward-convex arc shapes exist on the main surface profile, the thickness direction of the spacer The highest point can be designated as the starting position S of the inclined surface 1A. Furthermore, the shape of the main surface of spacer 1, in a radial cross-sectional view, is the edge on the inner circumferential side When it decreases monotonically towards the edge on the outer surface (a case that is not linear but decreases monotonically) Including. Hereinafter referred to as "approximately linear shape." See Figure 8(c). ), starting position of inclined surface 1A The element S can be the inner circumferential edge on the main surface.

[0030] The dropout amount D can be measured, for example, with an optical interferometer. Specifically, for example The measurement can be taken using the NIDEK FT-17 flatness tester. After acquiring the surface shape data, the radial cross-sectional shape of spacer 1 is analyzed (i.e., (The height data of the main surface of the spacer along any radial direction is displayed as a cross-sectional view and analyzed.) , the starting position S of the inclined surface 1A and the ending position of the inclined surface 1A (the boundary between the main surface and the chamfered surface on the outer periphery) Measure the height of each part in the ) and calculate the difference in the thickness direction (the difference in height between each part). This measurement is repeated every 90 degrees, using the center of spacer 1 as the reference point, to obtain four data points. The average of these values ​​can be taken as the amount of material removed from one main surface, D. As will be explained later... The main surface of spacer 1 is ground and polished using the same method as when manufacturing the substrate for magnetic disks. In this case, since a double-sided simultaneous processing device is basically used, the amount of material removed D from each of the pair of main surfaces is They will be almost the same. Furthermore, within the individual radial profile data, the outer region of the main surface does not fall out. In some cases, the outer edge on the main surface may be the highest point. The amount of the drop should be calculated by applying the opposite sign to the amount of the drop. For example, the height of the edge on the outer perimeter. Find the lowest height on the main surface profile and calculate the difference between the two in the thickness direction. Then, assign the opposite sign to the above-mentioned amount of deduction. By doing this, the other amounts of deduction Since it can be calculated together with the data, the average value of the amount of falloff for the main surface 4 is correct This allows for a clear understanding of the inclination of such an inclined surface 1A relative to the horizontal portion of the main surface 4. The inclination angle is, for example, 0 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 a chamfered surface.

[0031] According to one embodiment, the thickness of the magnetic disk 5 mounted on the HDD together with the spacer 1 is It is preferable that the thickness of the spacer 1 is 80% or less. The thickness of the magnetic disk 5 is the spacer It is more preferable that the thickness of S1 be 70% or less, and even more preferable that it be 50% or less. It seems that the thinner the thickness of the magnetic disk 5, the less pressure is applied by the clamp member 12. Because the disc 5 is more likely to penetrate and affect the spacer 1, the surface of the spacer 1 is subjected to pressure. The part that receives the magnetic field becomes more prone to deformation into a concave shape. When spacer 1 deforms into a concave shape, the magnetic field The magnetic disk 5 follows suit and bends significantly. Then the outer edge of the magnetic disk 5 The plate may shift from its predetermined position in the thickness direction, causing problems such as contact with a lamp. It happens. However, by using the spacer 1 of this embodiment, in the above case, Since the indentation of the pager 1 can be offset, the bending of the magnetic disk 5 can be effectively prevented. This can be done. In other words, the warping of the magnetic disk 5 can be suppressed. Thickness of spacer 1 The thickness 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. Yes. Also, there are no particular restrictions on the substrate material of the magnetic disk 5, but for example, glass substrate or aluminum A nium alloy substrate can be used. Among these, due to its relatively high rigidity, the space From the perspective of providing a high level of effectiveness, a glass substrate is more preferable.

[0032] Furthermore, according to one embodiment, the Young's modulus of the spacer 1 is the same as that of the substrate constituting the magnetic disk 5. It is preferable that it is smaller than the Young's modulus. This prevents localized pressing from the clamp member 12. The pressure is transmitted to the spacer 1 without deforming or damaging the magnetic disk 5. In addition to becoming easier, the main surface portion of the spacer 1 that is subjected to the pressing force by the clamp member 12 This makes it easier to dent, and as a result, it is possible to prevent dents in the main surface of spacer 1. In other words, the spacer 1 receives the above pressing force and changes the shape of the inclined surface 1A to a horizontal surface. It can be easily deformed in such a way. The Young's modulus of spacer 1 is, for example, 60~ The pressure is 200 [GPa], and the Young's modulus of the substrate constituting the magnetic disk 5 is, for example, 70 to 11. The pressure is 0 [GPa]. Note that when amorphous glass is used as the material for spacer 1. The Young's modulus of spacer 1 is preferably, for example, 60 to 100 [GPa].

[0033] The material of spacer 1 is not particularly limited; if glass is used as the material, aluminum is also an option. Nosilicate glass, soda-lime glass, soda-aluminosilicate glass, aluminobolo Examples include silicate glass, boron silicate glass, quartz glass, or crystallized glass. Among these, it is possible to improve the surface smoothness of spacer 1 and it is relatively easy to process. In this respect, amorphous glass is preferable. Aluminosilicate glass is For example, silicon dioxide (SiO2): 59-63% by mass, aluminum oxide (Al2O3 ): 5-16% by mass, lithium oxide (Li2O): 2-10% by mass, sodium oxide (N The composition is 2-12% by mass of a2O and 0-5% by mass of zirconium oxide (ZrO2). 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~ Amorphous glass with a composition of 17% by mass and 0-5% by mass of ZrO2 can be used. can.

[0034] The glass material that forms the basis of Spacer 1 was manufactured using methods such as the float method and the down-draw method. Glass cut into an annular shape from a sheet of glass, glass formed from molten glass using a pressing method, and glass drawn from a tube. This can be done by any method, such as slicing a legally manufactured glass tube to an appropriate length. Good. On the end face (outer or inner surface) or main surface of the annular-shaped glass formed in this manner. In contrast, grinding (including chamfering) and polishing are performed in the same manner as when manufacturing substrates for magnetic disks. It is possible. The method of grinding and polishing the end face is not particularly limited, for example, # Grinding or polishing is performed using a shaped grinding wheel containing diamond abrasive grains ranging from 80 to #1000. This can be done. Furthermore, grinding and polishing of the end faces may be performed using polishing brushes or polishing pads. Furthermore, grinding and polishing of the end faces are performed using an etching solution containing hydrofluoric acid or silicic acid. It may be done precisely. The inclined surface 1A of the main surface 4 can be ground or polished, or these It can be formed using both. For example, in the polishing process, alumina and silica A slurry containing abrasive particles and a soft, suede-type foamed polyurethane polishing pad By using this, the amount of material removed D mentioned above can be increased. On the other hand, cerium abrasive grains are included. By using a slurry and a suede-type polishing pad, the outer peripheral area of ​​the main surface can be polished upwards. It can be bent. Furthermore, the slurry concentration, the hardness of the polishing pad, and other conditions can be changed. By modifying or combining them, it is possible to create a flat main surface without an inclined surface, or to change the starting position of the inclined surface. S can also be adjusted.

[0035] The dimensions of the annular spacer 1 can be changed as appropriate depending on the specifications of the installed HDD. However, for a nominal 3.5-inch HDD device, the outer diameter is, for example, 30-34 mm. The inner diameter is, for example, 25 mm, and the thickness is, for example, 0.5 to 3 mm. Also, the chamfered surface (inner When a chamfered surface (circumferential or outer peripheral) is provided, the angle of the chamfered surface with respect to the main surface should be, for example, 20 to 70 degrees. The radius is 50-500 μm. The shape of the chamfered surface is radius In a cross-sectional view of the direction, it can be either a straight line or a curve. Furthermore, the dimensions of the magnetic disk 5 can be adjusted as needed depending on the specifications of the installed HDD. However, for a nominally 3.5-inch HDD device, the outer diameter is, for example, 85-100mm. 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, it is preferable that a conductive film is provided on the surface of the spacer 1. Examples of conductive film materials include nickel alloys such as nickel-phosphorus (NiP) and tin oxide. FTO (SnO2), zinc oxide (ZnO), titanium dioxide, and tin oxide doped with fluorine. conductive oxides such as AZO, which is zinc oxide doped with aluminum oxide (Al2O3), Examples include the following. 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 released 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 This reduces the adsorption of fine particles. It also prevents dust generation from the surface of the substrate of spacer 1. It is also possible. The substrate of the spacer 1 having a conductive film may be made of glass, ceramic, or It may also be made of metal.

[0037] According to one embodiment, the thickness of the magnetic disk 5 mounted on 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 of 0.55 mm or less, The pressing force from the ramp member 12 easily penetrates the magnetic disk 5 and affects the spacer 1. Therefore, the surface of spacer 1 is more likely to deform into a concave shape around the area that received the pressing force. Furthermore, because the magnetic disk 5 is thin, it easily conforms to the concave spacer 1. As a result... The magnetic disk 5 becomes more prone to bending. However, even in this case, the inclined surface 1A described above The spacer 1 is preferable because it can suppress and even prevent the above-mentioned deflection.

[0038] In an HDD device equipped with such a spacer 1 and magnetic disk 5, the mounted magnetic disk As the number of disks 5 increases, the clamping member 12 presses to secure the magnetic disks 5. The pressure needs to be increased. For this reason, with conventional spacers that do not have an inclined surface 1A, the mounting... The more magnetic disks 5 there are, the greater the curvature of the magnetic disks 5. However, the tilt By using the spacer 1 with surface 1A, even if the pressing force by the clamp member 12 is increased, the magnetic field will not be affected. This reduces the likelihood of the magnetic disk 5 warping. In this respect, a system equipped with nine or more magnetic disks 5 is less likely to warp. In an HDD device, the spacer 1 having an inclined surface 1A functions effectively. Also, 10 or more In the HDD device equipped with the above magnetic disk, the use of a spacer 1 having an inclined surface 1A This is even more effective. Also, for HDD devices equipped with 11 or more magnetic disks... Therefore, the use of spacer 1 having an inclined surface 1A is even more effective.

[0039] The main surface 4 of the spacer 1 shown in Figure 4 has a part of the main surface where the main surface 4 and the outer peripheral surface 2 are connected. The inclined surface 1A is such that the thickness of the spacer 1 decreases towards the corner in between. Furthermore, the inclined surface 1A extending toward the outer surface is a horizontal surface without inclination, and the portion on the inner surface is a horizontal surface without inclination. However, instead of a horizontal surface, the starting position of the inclined surface 1A is used to connect the main surface 4 and the inner circumferential surface 3. The inclined surface is such that the thickness of spacer 1 decreases towards the corner between them. This is also acceptable. In this case, the starting position S of the inclined surface 1A will be the point that protrudes the most upward.

[0040] Furthermore, one modified version of the present invention is a hard disk drive in which the main surface is magnetic It is a ring-shaped spacer that is positioned to be in contact with the disc. The main surface on at least one side of the spacer is, in part, Towards the corner between the main surface and the outer surface of the spacer, away from the magnetic disk The surface is inclined in such a way. In other words, at least one of the spacers The main surface on the side, in a part of the main surface, is the main surface of the spacer and the outer peripheral surface The angle between the two surfaces is inclined toward the main surface on the other side of the spacer. It is an inclined surface. Here, "corner" refers to the case where there is a chamfered surface between the main surface and the outer surface. This 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 in which the main surface is magnetic It is an annular spacer provided so as to be in contact with the disc. The main surface on the other side is, in part, the main surface of the spacer An inclined surface that slopes toward the corner between the outer surface and the spacer so that the thickness of the spacer decreases. That's how it is. [Examples]

[0042] Using an HDD equipped with 9 magnetic disks, the amount of material removed from the outer peripheral area of ​​the main surface of the spacer. D and the change in flatness (curvature) of the magnetic disk (the one fixed at the top) before and after clamping. We investigated the relationship with quantity. Specifically, we first examined the top magnetic disk from the HDD spindle. Then, the spacer directly beneath it was removed, and the flatness of the removed magnetic disk was measured. Next, , an arbitrary spacer whose drop amount D has been measured is placed with the surface on which the drop amount was measured facing upwards and spinned After attaching it to the spindle, the magnetic disk whose flatness had been measured in advance was then attached to the spindle, and finally The clamping member is used to tighten the surface, and the flatness of the top surface of the magnetic disk is then measured in that state. Measurements were taken. Any components that might interfere with the measurement (such as lamp components) were removed from the HDD beforehand. Note that the flatness (curvature) of the magnetic disk is measured by Optic, Inc. The maximum height difference on the surface of the magnetic disk was measured using a flatbed.

[0043] The specifications for the spacer and magnetic disk are as follows: • Spacer: Made of 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 mm on both the inner and outer sides. The thickness was set to 50 μm, with an angle of 45 degrees to the inner and outer surfaces. The width L of the main surface was 3.0 mm. By adjusting various manufacturing conditions for the spacers, the magnitude of the drop amount D on the inclined surface can be varied. They manufactured the . • Magnetic disk: A device made by depositing a magnetic film or the like on a glass substrate, with a Young's modulus of 8. The specifications were 0 GPa, 97 mm diameter, 25 mm inner diameter, and 0.5 mm plate thickness.

[0044] <Amount of reduction D> Four data points are obtained at 90-degree intervals on one main surface of a single spacer, and the average value is calculated. did. The sign of the elimination quantity D was determined as follows: The main surface profile slopes downwards (i.e., downwards) towards the other main surface as it moves towards the outer surface. In the case of the shape (i.e., the spacer of the present invention), the positive side is, conversely, the side toward the outer circumferential surface. The value increases with increasing pressure, with the highest point being the outer edge, which is considered negative.

[0045] <Change in flatness> The flatness of a magnetic disk is generally greater after clamping than before clamping. While the opposite is more common, the change in flatness is shown as an absolute value because it can also be the opposite. It can be used if the particle size is 4 μm or less, and preferably if it is 3 μm or less. It is possible, and more preferably usable if the particle size is 2.5 μm or less.

[0046] [Table 1]

[0047] As shown in the results above, by making the drop amount D greater than 0 (positive), the change in flatness amount becomes 4 It was found that the size could be reduced to less than μm. Also, by setting the amount of fallout D to 0.1 to 2.0 μm... Furthermore, it was found that the change in flatness could be reduced to 3 μm or less. In addition, the amount of drop D was set to 0.1 to 1 It was found that setting the thickness to 0.5 μm reduced the change in flatness to 2.5 μm or less.

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

[0049] 1. Glass spacer 1A Slope 2 Outer surface 3 Inner surface 4 Main surface 5 Magnetic disks 10. Hard disk drive device 12 Clamp member 14 protrusions 16 spindles 18 rotation axes

Claims

1. An annular spacer provided within a hard disk drive device such that its main surface is in contact with a magnetic disk, The spacer has a pair of main surfaces, an inner circumferential surface, and an outer circumferential surface, and there is a chamfered surface between each of the pair of main surfaces and the outer circumferential surface. On at least one of the pair of main surfaces, within the range of that main surface and in at least a portion of the outer peripheral region, there exists an inclined region that is inclined toward the other main surface in the radial direction from the center of the spacer toward the outer peripheral surface. The material of the spacer includes glass. A spacer characterized by the following features.

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

3. The spacer according to claim 1 or 2, wherein the inclined region is convex in the radial direction from the center of the spacer toward the outer circumferential surface.

4. An annular spacer provided within a hard disk drive device such that its main surface is in contact with a magnetic disk, The spacer has a pair of main surfaces, an inner circumferential surface, and an outer circumferential surface, and there is a chamfered surface between each of the pair of main surfaces and the outer circumferential surface. On at least one of the pair of main surfaces, within the range of that main surface and in at least a portion of the outer peripheral region, there exists a portion in which the radial cross-sectional shape extending from the center of the spacer toward the outer peripheral surface is an upwardly convex arc shape. The material of the spacer includes glass. A spacer characterized by the following features.

5. The spacer according to claim 4, wherein, in the cross-sectional shape of the main surface, 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 is 0.1 to 2 μm.

6. The spacer according to any one of claims 1 to 5, wherein the Young's modulus of the spacer is smaller than the Young's modulus of the substrate constituting the magnetic disk.

7. The spacer is the spacer according to any one of claims 1 to 6, wherein the spacer has a conductive film on its surface.

8. The spacer according to any one of claims 1 to 7, wherein the substrate of the magnetic disk is made of glass.

9. The spacer according to any one of claims 1 to 8, wherein the thickness of the magnetic disk is 0.55 mm or less.

10. A hard disk drive device comprising a spacer according to any one of claims 1 to 9.

11. The hard disk drive device according to claim 10, comprising 10 or more of the aforementioned magnetic disks.

12. The hard disk drive device according to claim 10, comprising 11 or more of the aforementioned magnetic disks.

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