Magnetic disk device and manufacturing method for magnetic disk device

Abstract

To provide a magnetic disk device and a manufacturing method for a magnetic disk device to enclose a desiccant that maintains hygroscopicity.SOLUTION: A magnetic disk device of the embodiment includes: a case formed by combining a base and a cover to form an airtight enclosure; a magnetic disk stored in the housing; a needle that protrudes upward into the interior space of the housing; and a desiccant assembly attached to the cover so as to face the base at a predetermined distance. The desiccant assembly includes a case having an opening portion in the surface facing the base, a sealed film provided on the opening portion, a split filter that divides the space inside the case into a first chamber and a second chamber including an opening, and a desiccant filled in the first chamber, in which the second chamber communicates with the interior space of the housing by a needle penetrating the sealing membrane.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] FIELD Embodiments of the present invention relate to a magnetic disk device and a method for manufacturing the magnetic disk device. [Background technology]

[0002] A magnetic disk drive has a housing that houses various components, including a magnetic disk. The housing has, for example, a base and a cover attached to the base. To reduce the rotational resistance of the magnetic disk, the inside of the housing is filled with He gas or the like.

[0003] In such magnetic disk drives, a desiccant may be enclosed to control humidity inside the housing. In order to maintain the hygroscopicity of the desiccant, it is preferable to limit the exposure of the desiccant to the atmosphere when enclosed inside the housing to a very short period of time. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2020 / 0066308 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of one embodiment is to provide a magnetic disk device capable of enclosing a desiccant that maintains hygroscopicity, and a method for manufacturing the magnetic disk device. [Means for solving the problem]

[0006] The magnetic disk device of the embodiment comprises a housing that is hermetically sealed by combining a base and a cover, a magnetic disk contained within the housing, a needle that protrudes upward into the internal space of the housing, and a desiccant assembly that is provided on the cover so as to face the base at a predetermined distance from the base, wherein the desiccant assembly has a case that has an opening on the surface facing the base, a sealing film that is provided on the opening, a dividing filter that divides the space within the case into a first chamber and a second chamber that includes the opening, and a desiccant filled in the first chamber, and the second chamber is connected to the internal space of the housing by the needle penetrating the sealing film. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is an exemplary exploded perspective view of a magnetic disk device according to a first embodiment. [Figure 2] FIG. 2 is a schematic diagram showing an example of the configuration of the desiccant assembly according to the first embodiment. [Figure 3] FIG. 3 is a schematic diagram showing an example of the procedure of the method for manufacturing the magnetic disk device according to the first embodiment. [Figure 4] FIG. 4 is a schematic diagram showing an example of the procedure of the method for manufacturing the magnetic disk drive according to the first embodiment. [Figure 5] FIG. 5 is a schematic diagram showing how a desiccant assembly according to a first modification of the first embodiment is assembled to a base. [Figure 6] FIG. 6 is a schematic diagram showing an example of a needle included in a magnetic disk device according to a second modification of the first embodiment. [Figure 7] FIG. 7 is an exemplary exploded perspective view of the magnetic disk device according to the second embodiment. [Figure 8] FIG. 8 is a schematic diagram showing an example of the configuration of a desiccant assembly according to the second embodiment. [Figure 9] FIG. 9 is a schematic diagram showing an example of the procedure of the method for manufacturing a magnetic disk drive according to the second embodiment. [Figure 10] FIG. 10 is a schematic diagram showing an example of the procedure of the method for manufacturing a magnetic disk drive according to the second embodiment. [Figure 11] FIG. 11 is a schematic diagram showing an example of a needle included in a magnetic disk device according to a first modification of the second embodiment. [Figure 12] FIG. 12 is a schematic diagram showing an example of the configuration of a desiccant assembly according to Modification 2 of Embodiment 2. As shown in FIG. [Figure 13] FIG. 13 is a schematic diagram showing some examples of needles included in a magnetic disk device according to a third modification of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the following embodiments. Furthermore, the components in the following embodiments include those that can be easily imagined by a person skilled in the art or those that are substantially the same.

[0009] [Embodiment 1] Hereinafter, the first embodiment will be described in detail with reference to the drawings.

[0010] (Example of magnetic disk device configuration) 1 is an exemplary exploded perspective view of a magnetic disk device 10 according to a first embodiment. The magnetic disk device 10 of the first embodiment is configured as, for example, an HDD (Hard Disk Drive). However, the magnetic disk device 10 of the first embodiment may be another magnetic disk device such as a hybrid HDD.

[0011] In this specification, the X direction, Y direction, and Z direction are defined for convenience. The X direction, Y direction, and Z direction are perpendicular to each other. The X direction is defined as the direction along the width of the magnetic disk device 10. The Y direction is appropriately defined as the direction along the depth of the magnetic disk device 10. The Z direction is defined as the direction along the thickness of the magnetic disk device 10, and may also be referred to as the up-down direction in this specification.

[0012] 1, a magnetic disk device 10 includes multiple magnetic disks 12, a spindle motor 13, multiple magnetic heads 14, a head stack assembly (HSA) 15, a voice coil motor (VCM) 16, a ramp load mechanism 17, a flexible printed circuit board (FPC) 18, a printed circuit board (PCB) 19, and a housing 20 that covers these components. The magnetic heads 14 are also called sliders.

[0013] The housing 20 has a base 21, an inner cover 22, and an outer cover 23. The base 21, the inner cover 22, and the outer cover 23 are made of metal such as aluminum alloy or stainless steel, but the base 21, the inner cover 22, and the outer cover 23 may also be made of other materials.

[0014] The base 21 is a container with a bottom, and has a bottom wall 211 and a side wall 212. The bottom wall 211 is formed in a substantially rectangular plate shape extending along the XY plane. The side wall 212 protrudes in the Z direction from the edge of the bottom wall 211. A plurality of screw holes 213 are formed in the upper surface of the side wall 212.

[0015] The inner cover 22 is formed in a substantially rectangular plate shape extending along the XY plane. The inner cover 22 has a plurality of insertion holes 223 at positions corresponding to the screw holes 213 provided in the side wall 212 of the base 21.

[0016] The inner cover 22 also has a plurality of recesses 221 that are slightly recessed from the top surface of the inner cover 22. These recesses 221 are provided in the inner cover 22 on the inside of the portion that overlaps the side wall 212 of the base 21 in the vertical direction, and a vent hole 222 or an insertion hole 223 that penetrates the inner cover 22 in the plate thickness direction is provided in the center of each of these recesses 221. Screw holes (not shown) are provided in some of the components housed in the base 21. The insertion hole 223 provided in the center of the recess 221 is positioned at a position that corresponds to the screw holes provided in some of these components. Stickers 225 are affixed to the vent holes 222 and the screwed insertion holes 223, respectively, to cover the vent holes 222 and the insertion holes 223.

[0017] Of the ventilation hole 222 or the insertion hole 223 provided in the center of the recess 221, only the ventilation hole 222 is shown in FIG.

[0018] A plurality of screws 224 are inserted into a plurality of insertion holes 223 of the inner cover 22 and fixed to a plurality of screw holes 213 of the base 21, whereby the inner cover 22 is attached to the end of the side wall 212 of the base 21 so as to overlap with the base 21 in the Z direction, and is also fixed to a member housed within the base 21. A gasket (not shown) is interposed between the inner cover 22 and the base 21.

[0019] The outer cover 23 is airtightly joined to the end of the side wall 212 of the base 21 by, for example, welding, so as to cover the inner cover 22.

[0020] This configuration seals the interior of the housing 20. The housing 20 accommodates the above-mentioned magnetic disk 12, spindle motor 13, magnetic head 14, HSA 15, VCM 16, ramp load mechanism 17, and FPC 18. The internal space of the housing 20 is filled with a gas having a density lower than that of air, such as He gas.

[0021] The magnetic disk 12 is, for example, a disk-shaped recording medium having a recording surface with a magnetic recording layer provided on the top surface, bottom surface, etc. In the example of Fig. 1, the diameter of the magnetic disk 12 is, for example, 3.5 inches. However, the magnetic disk 12 is not limited to this example.

[0022] The spindle motor 13 supports and rotates a plurality of magnetic disks 12 stacked at predetermined intervals in the Z direction, in which the recording surfaces of the disks face each other. As described above, the internal space of the housing 20 is filled with, for example, He gas. This prevents the magnetic disks 12 from experiencing air resistance when rotating at high speed, thereby reducing the rotational resistance of the magnetic disks 12.

[0023] The magnetic disk device 10 of the first embodiment configured as described above is also called a He-filled HDD or a He-sealed HDD. By filling the housing 20 with He gas or the like to reduce the rotational resistance of the magnetic disk 12, it becomes possible to configure the magnetic disk 12 thinner, and it becomes easy to increase the number of layers of the magnetic disk 12 and thereby increase the capacity of the magnetic disk device 10.

[0024] The magnetic disks 12 are held on the hub of the spindle motor 13 by, for example, clamp springs. In the example of Fig. 1, the magnetic disk device 10 has ten magnetic disks 12 arranged in the Z direction. However, the number of magnetic disks 12 is not limited to this example.

[0025] The magnetic head 14 records and reproduces information on the recording surface of the magnetic disk 12. In other words, the magnetic head 14 reads and writes information from and to the magnetic disk 12. The magnetic head 14 is mounted on the HSA 15.

[0026] The HSA 15 is rotatably attached to the base 21 at a position spaced apart from the magnetic disk 12 in a direction substantially perpendicular to the Z direction. The VCM 16 rotates the HSA 15 to position the magnetic head 14 at a desired position. The ramp load mechanism 17 holds the magnetic head 14, which has moved to the outermost periphery of the magnetic disk 12, at an unload position spaced apart from the magnetic disk 12.

[0027] The FPC 18 is supported and reinforced by an FPC plate provided on the bottom wall 211 of the base 21. One end of the FPC 18 is connected to a flexure included in the HSA 15. The FPC 18 is electrically connected to the magnetic head 14 via the flexure of the HSA 15. The other end of the FPC 18 is connected to a connector provided on the bottom wall 211 of the base 21.

[0028] The PCB 19 is attached to the outside of the housing 20, such as to the back surface of the bottom wall 211 of the base 21. Various electronic components are mounted on the PCB 19, such as a relay connector that is connected to the connector on the bottom wall 211 of the base 21, an interface (I / F) connector that is connected to a host computer, and a controller that controls the operation of the magnetic disk device 10. The relay connector is electrically connected to the FPC 18 via the connector on the bottom wall 211 of the base 21.

[0029] In a He-filled HDD such as the magnetic disk device 10 of the first embodiment, gases other than He gas and moisture can become sources of contamination inside the housing 20, so humidity control inside the housing 20 is important. Therefore, in the magnetic disk device 10 of the first embodiment, a desiccant assembly filled with desiccant is enclosed inside the housing 20.

[0030] (Example of desiccant assembly configuration) Next, a configuration example of the desiccant assembly 100 enclosed in the magnetic disk device 10 of the first embodiment will be described with reference to FIG.

[0031] Fig. 2 is a schematic diagram showing an example of the configuration of the desiccant assembly 100 according to the first embodiment. More specifically, Fig. 2(a) is a cross-sectional view of the desiccant assembly 100 enclosed in the magnetic disk device 10. Fig. 2(b) is a top view showing the internal structure of the magnetic disk device 10 in which the desiccant assembly 100 is enclosed.

[0032] As shown in FIG. 2, the desiccant assembly 100 of the first embodiment is provided on the inner surface of the inner cover 22 of the housing 20 so as to fit into an empty space within the housing 20, such as an area surrounded by the HSA 15, the VCM 16, and the FPC 18.

[0033] The desiccant assembly 100 includes a case 110 , a sealing film 120 , a filter 130 , and a desiccant 140 .

[0034] Case 110 is made of resin and has a shape such as a rectangular parallelepiped with an internal space. However, case 110 may also be made of metal. In this case, case 110 may be made of the same metal as inner cover 22, such as aluminum alloy or stainless steel, or case 110 and inner cover 22 may be molded integrally.

[0035] The upper surface of the case 110 is attached to the inner surface of the inner cover 22, and the lower surface has an opening 111 on the side facing the base 21. A sealing film 120 is fitted into the opening 111, and is airtight and does not allow air, gases such as He, or moisture in gases to pass through. The sealing film 120 is, for example, a thin film made of aluminum.

[0036] A filter 130 is provided within the case 110, dividing the space within the case 110 in a direction along the inner surface of the inner cover 22. The filter 130 is, for example, a membrane filter made of PTFE (Poly-Tetra-Fluoro-Ethylene), and is permeable to air, gases such as He, and moisture in gases. The filter 130 is an example of a dividing filter that divides the space within the case 110 into two spaces 110r and 110f.

[0037] Of the two spaces 110r, 110f within the case 110 separated by the filter 130, the space 110r on the side having the opening 111 into which the sealing film 120 is fitted is filled with a desiccant 140 capable of adsorbing moisture and the like in the gas in the space 110f on the far side thereof. Of the two spaces 110r, 110f within the case 110 separated by the filter 130, the other space 110r is maintained hollow.

[0038] Here, adsorbents that adsorb moisture and the like in gases include reversible adsorbents and irreversible adsorbents. Even if a reversible adsorbent's hygroscopicity decreases after adsorbing moisture, it can be restored by subsequent vacuum drying or the like. Irreversible adsorbents cannot restore their hygroscopicity once it has decreased by vacuum drying or the like, and are also difficult to regenerate at temperatures below 80°C, which is the upper limit of the heat resistance of the magnetic disk device 10. On the other hand, irreversible adsorbents can maintain their hygroscopicity even in low-humidity environments of 10% or less, where reversible adsorbents do not function.

[0039] In the magnetic disk device 10 of the first embodiment, although it is difficult to recover the reduced moisture absorption property, an irreversible adsorbent that has excellent moisture absorption property even in a low humidity environment is used as the desiccant 140. As the irreversible desiccant 140, for example, a synthetic zeolite such as a molecular sieve can be used.

[0040] Of the two spaces 110r, 110f within the case 110 separated by the filter 130, the space 110f filled with the desiccant 140 and the space 110r which remains hollow are examples of the first chamber and the second chamber, respectively.

[0041] A needle 216 is provided on the bottom wall 211 of the base 21 that constitutes the housing 20 of the magnetic disk device 10, and protrudes into an empty space within the housing 20 that houses the desiccant assembly 100. More specifically, the needle 216 is provided at a position that overlaps vertically with the opening 111 provided in the case 110 of the desiccant assembly 100, and the protruding height of the needle 216 is located above the bottom surface of the case 110, i.e., the surface facing the base 21.

[0042] The needle 216 is made of the same metal as the base 21, such as aluminum alloy or stainless steel, and is integrally formed with the base 21. This reduces the number of parts in the magnetic disk device 10. However, the needle 216 may be made of a different material from the base 21, such as resin or another metal, and may be attached to the base 21 as a separate part.

[0043] The needle 216 penetrates the sealing film 120 of the desiccant assembly 100 , and the upper end of the needle 216 reaches into the space 110 r within the case 110 of the desiccant assembly 100 .

[0044] When the needle 216 penetrates in this manner, a portion of the sealing film 120 is broken, creating a gap, and the space 110r inside the case 110 of the desiccant assembly 100 is in communication with the internal space of the housing 20. This allows the desiccant 140 filled inside the case 110 of the desiccant assembly 100 to absorb moisture inside the housing 20 through the filter 130, the space 110r inside the case 110, and the gap in the sealing film 120.

[0045] By exposing the desiccant 140 to the atmosphere inside the housing 20 through the filter 130, dust and other particles that may be generated from the desiccant 140 can be removed by the filter 130, thereby preventing the inside of the housing 20 from becoming contaminated.

[0046] (Magnetic Disk Drive Manufacturing Method) Next, a method for manufacturing the magnetic disk device 10 according to the first embodiment will be described with reference to Figures 3 and 4. Figures 3 and 4 are schematic diagrams showing an example of the procedure for the method for manufacturing the magnetic disk device 10 according to the first embodiment.

[0047] In the manufacturing process of the magnetic disk device 10, first, in the base 21 provided with the needle 216, the plurality of magnetic disks 12, the spindle motor 13, the magnetic head 14, the HSA 15, the VCM 16, the ramp load mechanism 17, and the FPC 18 are assembled so as to be operable as the magnetic disk device 10. In other words, these magnetic disks 12, the spindle motor 13, the magnetic head 14, the HSA 15, the VCM 16, the ramp load mechanism 17, and the FPC 18 are housed in the space within the base 21 so as to be operable.

[0048] Meanwhile, the desiccant assembly 100 is attached to the inner surface of the inner cover 22. The inner cover 22 is then overlapped with the base 21, for example, with a gasket or the like (not shown) interposed therebetween, and screws 224 are inserted into the insertion holes 223 of the inner cover 22 and fixed to the screw holes 213 of the base 21. After the screws are fastened, a seal 225 is attached to the insertion holes 223 provided in the recess 221 near the center of the inner cover 22. At this time, the PCB 19 connected to the FPC 18 is also attached to the back surface of the base 21 or the like with these screws 224.

[0049] In this way, the inner cover 22 is airtightly attached to the base 21. The state in which the inner cover 22 is attached to the base 21 is shown in the cross-sectional view of FIG.

[0050] 3(a), the inner surface of the inner cover 22 to which the desiccant assembly 100 is attached is made to face the base 21 which houses the magnetic disk 12 and the like. The attachment position of the desiccant assembly 100 to the inner cover 22 is adjusted so that the opening 111 provided in the case 110 and into which the sealing film 120 is fitted is vertically overlapped with the needle 216 provided in the base 21.

[0051] Also, at the stage shown in Figure 3(a), the inside of the case 110 of the desiccant assembly 100 is sealed by a sealing film 120 fitted into the opening 111, and is kept at least in a dry state that does not contain moisture, etc.

[0052] 3(b), by overlapping the inner cover 22 on the base 21, the needles 216 provided on the base 21 pierce the sealing film 120 at the opening 111 of the case 110, creating a gap in part of the sealing film 120. In addition, with the inner cover 22 overlapping the base 21, the lower surface of the case 110 is located above the bottom wall 211 of the base 21 without contacting the bottom wall 211, creating a gap between the case 110 and the bottom wall 211 of the base 21.

[0053] As a result, the opening 111 of the case 110 is not blocked by the bottom wall 211 of the base 21, and the space 110r inside the case 110 communicates with the spaces inside the inner cover 22 and the base 21. Therefore, the desiccant 140 filled in the case 110 is exposed to the atmosphere in the internal space formed by the inner cover 22 and the base 21 through the filter 130, the space 110r inside the case 110, and the gaps in the sealing film 120.

[0054] The internal space defined by the inner cover 22 and the base 21 is initially filled with air containing moisture, etc. However, immediately after the inner cover 22 is screwed to the base 21, the air inside the inner cover 22 and the base 21 is sucked through the ventilation holes 222 provided in the inner cover 22. Furthermore, He gas is filled inside the inner cover 22 and the base 21 through the ventilation holes 222.

[0055] However, for example, by using other holes provided in the inner cover 22 in combination, the space within the inner cover 22 and the base 21 may be filled with He gas through the ventilation hole 222, and the air within the space may be discharged through the other holes. Other holes that may be provided in the inner cover 22 include, for example, a dust measurement port (not shown).

[0056] The above-described air evacuation and He gas filling are performed promptly after the inner cover 22 and the base 21 are assembled. This allows the progress of moisture adsorption in the air, which begins by the desiccant 140 at the timing when the needle 216 penetrates the sealing film 120, to be limited to a short time, thereby suppressing a decrease in the moisture absorption performance of the desiccant 140.

[0057] 4(a), a seal 225 is then attached to the ventilation hole 222 of the inner cover 22. When the ventilation hole 222 is closed with the seal 225 in this manner, the internal space defined by the inner cover 22 and the base 21 is sealed and filled with He gas.

[0058] As shown in FIG. 4( b ), an outer cover 23 is further superimposed on the inner cover 22 , and the outer cover 23 is welded to the end of the side wall 212 of the base 21 .

[0059] In this manner, the magnetic disk device 10 of the first embodiment is manufactured.

[0060] As described above, the desiccant assembly 100 is maintained in a sealed state until immediately before the inner cover 22 is attached to the base 21. Furthermore, when the base 21 and the inner cover 22 are assembled, the desiccant assembly 100 is opened by the needle 216, and then the air in the internal space defined by the base 21 and the inner cover 22 is quickly replaced with He gas. This makes it possible to limit exposure of the desiccant 140 to the atmosphere during the manufacturing process and obtain a magnetic disk drive 10 in which the desiccant 140 is sealed while maintaining high moisture absorption performance.

[0061] (Overview) In recent years, helium-sealed HDDs, in which helium gas is sealed inside the housing, have become the mainstream for large-capacity magnetic disk drives. In helium-sealed HDDs, humidity control inside the housing is an important issue to improve the reliability of the magnetic disk drive. Humidity can have a particularly significant effect on HDDs that use the heat-assisted magnetic recording (HAMR) method, which writes information using heat assistance.

[0062] Therefore, in He sealed HDDs, humidity inside the housing is controlled by sealing in a desiccant, for example. If the desiccant is exposed to the atmosphere for a long period of time during the assembly process of the magnetic disk drive, there is a concern that the desiccant may be sealed in with reduced moisture absorption performance or may become saturated before the housing is sealed.

[0063] The above-mentioned Patent Document 1 discloses a method in which a case containing a desiccant sealed with an aluminum seal is placed inside an apparatus, and the desiccant is opened by drilling a hole in the aluminum seal inside the apparatus through a hole in the cover. However, the method of Patent Document 1 requires an additional hole drilling process, which has the drawback of lengthening the takt time.

[0064] According to the magnetic disk device 10 of embodiment 1, the desiccant assembly 100 includes a case 110 having an opening 111 on the surface facing the base 21, a sealing film 120 covering the opening 111, a filter 130 dividing the space within the case 110 into a space 110f and a space 110r including the opening 111, and a desiccant 140 filled in the space 110f, and the space 110r is connected to the internal space of the housing 20 by a needle 216 provided on the base 21 penetrating the sealing film 120.

[0065] This allows the desiccant 140 to be enclosed while maintaining its hygroscopicity. This allows strict humidity control within the housing 20, improving the reliability of the magnetic disk device 10. In the HAMR type magnetic disk device 10, it is possible to further improve the reliability.

[0066] According to the magnetic disk device 10 of the first embodiment, the filter 130 extends in a direction intersecting the inner surface of the inner cover 22 and divides the space inside the case 110 in a direction along the inner surface of the inner cover 22, and the two divided spaces 110r, 110f are arranged side by side in a direction along the inner surface of the inner cover 22. By arranging the two spaces 110r, 110f in this manner, the desiccant 140 can absorb moisture in the internal space of the housing 20 through the filter 130, the space 110r, and a gap in the sealing film 120 provided at the opening 111.

[0067] According to the manufacturing method of the magnetic disk device 10 of embodiment 1, the base 21 and the inner cover 22 are overlapped, and the needle 216 protruding from the base 21 side is brought into contact with the sealing film 120, and at least a portion of the sealing film 120 is removed from the opening 111 of the case 110 by the needle 216, thereby connecting the space 110r within the case 110 to the internal space of the housing 20, and the desiccant assembly 100 is positioned facing the base 21 at a position a predetermined distance from the base 21.

[0068] This allows the desiccant 140 to be kept sealed until just before the inner cover 22 and the base 21 are assembled, thereby limiting the exposure of the desiccant 140 to the atmosphere for a short period of time, and making it possible to obtain a magnetic disk device 10 in which the desiccant 140 is enclosed and whose hygroscopicity is maintained.

[0069] Furthermore, the desiccant assembly 100 can be easily opened at the same time as the inner cover 22 and the base 21 are assembled, and unlike Patent Document 1, for example, no special tool is required for opening the desiccant assembly 100. Furthermore, the number of manufacturing steps is not increased, and the takt time can be shortened. It is also possible to prevent forgetting to open the desiccant assembly 100.

[0070] Furthermore, since the desiccant assembly 100 is positioned a predetermined distance away from the base 21, the opening 111 of the case 110 is prevented from being blocked by the bottom wall 211 of the base 21, and the desiccant 140 can capture moisture inside the housing 20 even after the housing 20 is assembled.

[0071] (Variation 1) Next, a desiccant assembly 100a according to a first modification of the first embodiment will be described with reference to Fig. 5. The desiccant assembly 100a according to the first modification differs from the desiccant assembly 100 according to the first embodiment in the mechanism for opening the desiccant assembly 100a.

[0072] 5 is a schematic diagram showing how a desiccant assembly 100a according to Modification 1 of Embodiment 1 is assembled to a base 21. In the following drawings, the same components as those in the above-described Embodiment 1 are denoted by the same reference numerals, and their description may be omitted.

[0073] 5(a), the desiccant assembly 100a of the first modification includes a case 110a having an inner chamber 113. The inner chamber 113 of the case 110a is provided in a space 110r and is configured in a box shape that covers the opening 111.

[0074] That is, inner chamber 113 has a side wall 113s that surrounds the outer edge of opening 111, and an inner lid 113t that is provided at the upper end of side wall 113s to cover opening 111 and form the upper surface of inner chamber 113. One or more openings 114 are provided in side wall 113s of inner chamber 113. By providing openings 114 in side wall 113s in this manner, the internal space of box-shaped inner chamber 113 communicates with space 110r within case 110a.

[0075] Furthermore, it is preferable that the inner lid 113t of the inner chamber 113 is positioned at a height approximately equal to the upper end of the needle 216 that protrudes into the space 110r of the case 110a when the inner cover 22 is assembled to the base 21, or at a position slightly higher than the upper end of the needle 216.

[0076] A sealing film 120a is fitted into the opening 111 of the case 110a. The sealing film 120a is airtight and does not allow air, gases such as He, or moisture in gases to pass through. The sealing film 120a is a thin film made of resin such as silicone rubber or fluororubber.

[0077] At the stage shown in Figure 5(a), the inside of the case 110a of the desiccant assembly 100a is sealed by a sealing film 120a fitted into the opening 111 of the case 110a, and is kept at least in a dry state free from moisture, etc.

[0078] 5(b), when the inner cover 22 to which the desiccant assembly 100a is attached is placed on the base 21, the needle 216 provided on the base 21 hits the sealing film 120a. As described above, the sealing film 120a is made of a relatively strong material such as resin. Therefore, the sealing film 120a is pushed upward by the needle 216 without being torn, and is sandwiched between the upper end of the needle 216 and the inner lid 113t of the inner chamber 113.

[0079] In this way, by removing the sealing film 120a with the needle 216, the opening 111 of the case 110a is opened, and the space 110r inside the case 110a and the spaces inside the inner cover 22 and the base 21 communicate with each other.

[0080] According to the magnetic disk drive of Modification 1, the desiccant assembly 100a includes a case 110a having an opening 111 on a surface facing the base 21, an inner lid 113t disposed above the opening 111, and a sealing film 120a pressed against the surface of the inner lid 113t facing the opening 111. The needle 216 is inserted into a space 110r in the case 110a through the opening 111 and abuts against the underside of the inner lid 113t via the sealing film 120a. This allows the desiccant 140, whose hygroscopicity is maintained, to be enclosed.

[0081] In addition, the magnetic disk device of the first modification provides the same effects as the magnetic disk device 10 of the first embodiment described above.

[0082] (Variation 2) Next, a magnetic disk device according to a second modification of the first embodiment will be described with reference to Fig. 6. The magnetic disk device according to the second modification includes a needle 216d having a different shape from the needle 216 of the first embodiment described above.

[0083] 6 is a schematic diagram showing an example of a needle 216d included in a magnetic disk device according to Modification 2 of Embodiment 1. In the following drawings, the same components as those in the above-described Embodiment 1 are denoted by the same reference numerals, and their description may be omitted.

[0084] As shown in Fig. 6, the base 21d of the second modification includes a needle 216d having an extension 219ax and a piercing portion 219tp. The extension 219ax corresponds to the main body of the needle 216d, and penetrates the sealing film 120 to extend in the vertical direction of the sealing film 120. The piercing portion 219tp is located at the upper end of the extension 219ax, and has at least a portion having a cross section larger than that of the extension 219ax. As in the example shown in Fig. 6, the piercing portion 219tp may have a pointed tip, such as a cone shape.

[0085] Because the needle 216d of Modification 2 has such a shape, when the inner cover 22 and the base 21d are assembled, the piercing portion 219tp of the needle 216d penetrates the sealing film 120, thereby forming a larger hole HL in the sealing film 120. After the inner cover 22 and the base 21d are assembled, an extension portion 219ax having a smaller cross-sectional area than the piercing portion 219tp is positioned inside the hole HL formed in the sealing film 120.

[0086] According to the magnetic disk device of Modification 2, the needle 216d has an extension 219ax that extends through the sealing film 120, and a piercing portion 219tp that is provided at the upper end of the needle 216d and has at least a portion with a larger cross-sectional area than the extension 219ax. This allows a larger hole HL to be provided in the sealing film 120, and moisture inside the housing is collected through this hole HL, thereby further improving the moisture absorption efficiency of the desiccant 140.

[0087] In addition, the magnetic disk device of the second modification provides the same effects as the magnetic disk device 10 of the first embodiment described above.

[0088] [Embodiment 2] Hereinafter, the second embodiment will be described in detail with reference to the drawings. The magnetic disk device of the second embodiment includes a desiccant assembly having a different configuration from that of the first embodiment. In the following drawings, the same components as those of the first embodiment are denoted by the same reference numerals, and their description may be omitted.

[0089] (Example of magnetic disk device configuration) Fig. 7 is an exemplary exploded perspective view of a magnetic disk device 30 according to embodiment 2. More specifically, Fig. 7(a) shows the inside of the base 21e of the magnetic disk device 30, and Fig. 7(b) shows the inner surface of the inner cover 22 of the magnetic disk device 30. Fig. 7(c) is a see-through perspective view of the magnetic disk device 30.

[0090] As shown in FIG. 7(a), the base 21e of the magnetic disk device 30 accommodates a magnetic disk 12, a spindle motor 13, a magnetic head 14, an HSA 15, a VCM 16, a ramp load mechanism 17, an FPC 18, and an FPC plate 215, similar to the first embodiment described above.

[0091] As described above, the FPC plate 215 is a resin member for supporting and reinforcing the FPC 18, and is disposed on the bottom wall 211 of the base 21e. In the second embodiment, the needles 216e are provided on the upper surface of the FPC plate 215. By providing the needles 216e on the FPC plate 215 in this manner, it becomes easier to mount the FPC 18 in the limited space within the base 21e.

[0092] The needles 216e of the second embodiment are made of resin, for example, like the FPC plate 215, and are molded integrally with the FPC plate 215. This reduces the number of parts in the magnetic disk device 30. However, the needles 216e may be made of a different material, such as a metal, from the FPC plate 215 and embedded in the FPC plate 215.

[0093] 7(b), the desiccant assembly 300 of the second embodiment is attached to the inner surface of the inner cover 22 of the magnetic disk device 30, that is, the surface that faces the base 21e when the magnetic disk device 30 is assembled to the base 21e. More specifically, the desiccant assembly 300 is attached to the inner surface of the inner cover 22 at a position that overlaps with the ventilation opening 222 provided in the inner cover 22.

[0094] As shown in FIG. 7(c), when the base 21e and the inner cover 22 are assembled, the desiccant assembly 300 is positioned so as to overlap vertically with the needles 216e of the FPC plate 215 mounted on the base 21e.

[0095] (Example of desiccant assembly configuration) Next, a detailed configuration example of the desiccant assembly 300 of the second embodiment will be described with reference to FIG.

[0096] 8 is a schematic diagram showing an example of the configuration of a desiccant assembly 300 according to embodiment 2. In FIG. 8, an example of the configuration of the desiccant assembly 300 alone before being attached to the inner cover 22 is shown.

[0097] More specifically, Fig. 8(A) is a perspective view showing the overall configuration of the desiccant assembly 300, and Fig. 8(B) is a luxury cross-sectional view showing the overall configuration of the desiccant assembly 300. Fig. 8(C) shows the case 310 of the desiccant assembly 300, Fig. 8(Ca) is a perspective view of the case 310, and Fig. 8(Cb) is a top view of the case 310. Fig. 8(D) shows the sealing film 320 attached to the case 310 of the desiccant assembly 300, and Fig. 8(Da) is a perspective view of the back side of the sealing film 320, and Fig. 8(Db) is a perspective view of the top side of the sealing film 320.

[0098] As shown in Fig. 8(A), the desiccant assembly 300 before attachment includes a case 310, a sealing film 320, and a release sheet 360. The case 310 has, for example, a cylindrical shape with substantially flat upper and lower surfaces. The sealing film 320 is attached to the lower surface of the case 310, that is, the surface that will face the FPC plate 215 on the base 21e when attached to the inner cover 22. The release sheet 360 is attached to the upper surface of the case 310, that is, the surface that will be attached to the inner cover 22.

[0099] 8(B), case 310 has opening 311 on the bottom surface, and flow path 312 and vent 313 on the top surface. Inside case 310, filter 330 is provided, which extends in a direction along the top and bottom surfaces of case 310 and divides the space inside case 310 into two spaces 310r and 310f in the vertical direction.

[0100] However, the case 310 itself may be configured with two cases each including the spaces 310r and 310f. In this case, these two cases may be bonded together via the filter 330 or may be joined together to form a single unit as the case 310 that includes the two spaces 310r and 310f.

[0101] The filter 330 is, like the filter 130 of the first embodiment, a membrane filter made of, for example, PTFE, and is configured to be permeable to air, gases such as He, and moisture in gases, etc. The filter 330 of the second embodiment is an example of a divided filter that divides the space inside the case 310 into two spaces 310r and 310f.

[0102] Of the two spaces 310r, 310f within the case 310 separated by the filter 330, the space 310r is located on the lower surface side of the case 310, including an opening 311 provided on the lower surface of the case 310. The sealing film 320 is attached to the lower surface of the case 310 so as to cover the opening 311 and seal the space 310r and the like within the case 310.

[0103] Of the two spaces 310r, 310f within case 310 separated by filter 330, space 310f is located on the upper surface of case 310, and includes vent holes 313 and the like provided on the upper surface of case 310. Release sheet 360 is attached to the upper surface of case 310 with annular double-sided tape 350. Release sheet 360 is, for example, a thin film made of aluminum.

[0104] The double-sided tape 350 is formed in a circular ring shape as described above, and the outer edge of the release sheet 360 is attached to the outer edge of the top surface of the case 310, excluding the flow path 312 and the vent 313. In this way, the release sheet 360 covers the flow path 312 and the vent 313, and seals the space 310f inside the case 310.

[0105] Space 310f within case 310 is filled with desiccant 340. In the second embodiment as well, an irreversible adsorbent such as a synthetic zeolite, for example, a molecular sieve, can be used as desiccant 340. Furthermore, filter 330 in the second embodiment also has a function of collecting dust generated from desiccant 340. Meanwhile, space 310r within case 310 remains hollow.

[0106] Of the two spaces 310r, 310f within the case 310 separated by the filter 330, the space 310t filled with the desiccant 340 and the space 310r that remains hollow are examples of the first chamber and the second chamber, respectively.

[0107] 8(C), a plurality of flow paths 312 on the top surface of case 310 extend radially from, for example, a central portion. Ventilation holes 313 penetrating the top surface of case 310 in the thickness direction are connected to the ends of each of the plurality of radially extending flow paths 312. As described above, these flow paths 312 and ventilation holes 313 are closed by a release sheet 360 attached to the top surface of case 310.

[0108] As shown in FIG. 8(D), the sealing film 320 attached to the bottom surface of the case 310 is, for example, a thin film made of aluminum.

[0109] A thin portion 321 is provided by further thinning the thin-film sealing film 320 at the center of the back side of the sealing film 320, that is, the surface that faces the FPC plate 215 on the base 21e when attached to the inner cover 22. As shown in Fig. 8(Da), the thin portion 321 has a shape such as a cross so that the needles 216e of the FPC plate 215 can easily pierce it.

[0110] An adhesive layer 322 of adhesive or the like is provided in a circular shape on the outer periphery of the upper surface of the sealing film 320, i.e., the surface that is attached to the underside of the case 310. This adhesive layer 322 adheres the sealing film 320 to the outer edge of the underside of the case 310, excluding the opening 311 of the case 310, so that the sealing film 320 closes the opening 311 and seals the space 310r and the like within the case 310. Furthermore, since the annular adhesive layer 322 is positioned excluding the opening 311 of the case 310, it does not prevent the needle 216e of the FPC plate 215 from penetrating the sealing film 320, and also prevents the adhesive layer 322 from becoming a source of contamination after the sealing film 320 is broken.

[0111] In this manner, the sealing film 320 and the adhesive layer 322 are configured as a whole as, for example, an aluminum seal.

[0112] With the above configuration, when the desiccant assembly 300 is used alone before being attached to the inner cover 22, the inside of the case 310 of the desiccant assembly 300 is sealed by the sealing film 320 attached to the opening 311 and the peel-off sheet 360 attached to the flow path 312 and the ventilation hole 313, and is kept in a dry state that is at least free from moisture, etc.

[0113] (Magnetic Disk Drive Manufacturing Method) Next, a method for manufacturing the magnetic disk device 30 according to the second embodiment will be described with reference to Figures 9 and 10. Figures 9 and 10 are schematic diagrams showing an example of the procedure for the method for manufacturing the magnetic disk device 30 according to the second embodiment.

[0114] In the second embodiment as well, the plurality of magnetic disks 12, the spindle motor 13, the magnetic head 14, the HSA 15, the VCM 16, the ramp load mechanism 17, and the FPC 18 are assembled in the base 21e so as to be operable as the magnetic disk device 10. At this time, the needles 216e are provided, and the FPC plate 215 that supports the FPC 18 is also installed in the base 21e.

[0115] On the other hand, a desiccant assembly 300 is attached to the inner surface of the inner cover 22 .

[0116] That is, the release sheet 360 of the desiccant assembly 300 is peeled off to expose the double-sided tape 350 on the upper surface of the case 310. At this time, the desiccant 340 inside the case 310 is exposed to the atmosphere through the flow path 312 and the vent hole 313, so the step of attaching the desiccant assembly 300 to the inner cover 22 is preferably performed immediately before assembling the inner cover 22 to the base 21e.

[0117] Furthermore, when release sheet 360 is peeled off and desiccant 340 is exposed to the atmosphere, air spreads radially from the center of case 310 through flow path 312 and reaches desiccant 340 through vent 313. This prevents air from flowing into desiccant 340 all at once, preventing the moisture absorption reaction of desiccant 340 from progressing too quickly. A rapid moisture absorption reaction of desiccant 340 could significantly reduce the moisture absorption performance of desiccant 340.

[0118] The desiccant assembly 300 from which the release sheet 360 has been peeled off is attached to the inner surface of the inner cover 22 with double-sided tape 350. At this time, the attachment position of the desiccant assembly 300 is adjusted so that the central portion of the top surface of the case 310 overlaps with the ventilation opening 222 provided in the inner cover 22.

[0119] The ventilation hole 313 provided in the case 310 is an example of a second ventilation hole, and the ventilation hole 222 provided in the inner cover 22 and connected to the ventilation hole 313 of the case 310 is an example of a first ventilation hole.

[0120] Even after the desiccant assembly 300 is attached to the inner surface of the inner cover 22, the desiccant 340 in the case 310 continues to be exposed to the outside air through the flow path 312 and the vent 313 provided in the case 310 and the vent 222 of the inner cover 22. Therefore, until the inner cover 22 is assembled to the base 21e, a temporary fixing seal 225p is attached to the vent 222 of the inner cover 22 to which the desiccant assembly 300 is attached.

[0121] The inner cover 22 to which the desiccant assembly 300 is attached as described above is attached to the base 21e which houses a plurality of magnetic disks 12 and the like and on which the FPC plate 215 is installed. This state is shown in the cross-sectional view of FIG.

[0122] 10(a), the inner surface of the inner cover 22 to which the desiccant assembly 300 is attached is made to face the base 21e that houses the magnetic disk 12, etc. By attaching the desiccant assembly 300 to the position of the vent 222 of the inner cover 22, the opening 311 provided in the case 310 and to which the sealing film 320 is attached is positioned so as to overlap vertically with the needle 216e provided on the FPC plate 215 of the base 21e.

[0123] Also, at the stage shown in Figure 10(a), the inside of the case 310 of the desiccant assembly 300 is sealed by a sealing film 320 attached to the opening 311 and a temporary fixing seal 225p attached to the ventilation hole 222 of the inner cover 22.

[0124] 10(b), by overlapping the inner cover 22 on the base 21e, the needles 216e provided on the FPC plate 215 of the base 21e pierce the sealing film 320 that closes the opening 311 of the case 310, creating a gap in part of the sealing film 320. In addition, with the inner cover 22 overlapping the base 21e, the lower surface of the case 310 is located above the FPC plate 215 without contacting the upper surface of the FPC plate 215, creating a gap between the case 310 and the upper surface of the FPC plate 215.

[0125] As a result, the opening 311 of the case 310 is not blocked by the upper surface of the FPC plate 215, and the space 310r inside the case 310 communicates with the spaces inside the inner cover 22 and the base 21e. Therefore, the desiccant 340 filled inside the case 310 is exposed to the atmosphere in the internal space formed by the inner cover 22 and the base 21e through the filter 330, the space 310r inside the case 310, and the gap between the sealing film 320.

[0126] Thereafter, after the inner cover 22 is screwed to the base 21e, the air in the internal space between the inner cover 22 and the base 21e is quickly replaced with He gas through the ventilation holes 222 provided in the inner cover 22. At this time, too, He gas may be filled after the air has been discharged, or the air may be discharged as He gas is filled by using another hole such as a dust measurement hole in combination.

[0127] It is preferable that the vent 222 of the inner cover 22 to which the desiccant assembly 300 is connected is used solely for injecting He gas into the internal space between the inner cover 22 and the base 21e, and that air is sucked from the internal space via other holes. This allows the moisture absorption function of the desiccant 340 to allow He gas to flow into the internal space between the inner cover 22 and the base 21e in a drier state.

[0128] Even in this case, the filter 330 of the second embodiment still exhibits a dust collection function to prevent dust in the outside air from flowing into the internal space between the inner cover 22 and the base 21e. In addition, the flow rate of the outside air into the desiccant 340 is reduced by the flow path 312 and the vent 313 provided on the top surface of the case 310, thereby suppressing the rapid progress of the moisture absorption reaction of the desiccant 340.

[0129] After filling the internal space between the inner cover 22 and the base 21e with He gas, the vent hole 222 of the inner cover 22 is closed with a seal 225 to seal the internal space formed by the inner cover 22 and the base 21e. An outer cover 23 is further placed on the inner cover 22, and the outer cover 23 is welded to the end of the side wall 212 of the base 21e.

[0130] In this way, the magnetic disk device 30 of the second embodiment is manufactured.

[0131] (Overview) According to the magnetic disk device 30 of the second embodiment, the filter 330 of the desiccant assembly 300 extends in a direction along the inner surface of the inner cover 22 and divides the space inside the case 310 in a direction intersecting the inner surface of the inner cover 22, and the space 310f inside the case 310 is disposed between the space 310r inside the case 310 and the inner cover 22. By disposing the two spaces 310r, 310f in this manner, the desiccant 340 can absorb moisture in the internal space of the housing through the filter 330, the space 310r, and the gap in the sealing film 320 attached to the opening 311.

[0132] According to the magnetic disk device 30 of embodiment 2, the inner cover 22 has a vent 222 penetrating the inner cover 22, and the case 310 of the desiccant assembly 300 has a vent 313 connecting the vent 222 of the inner cover 22 to the space 310f inside the case 310 in which the desiccant 340 is filled.

[0133] This allows the atmosphere in the internal space between the inner cover 22 and the base 21e to be replaced via the vent 222 of the inner cover 22 and the vent 313 on the top surface of the case 310. At this time, if the vent 222 provided in the inner cover 22 and connected to the desiccant assembly 300 is used to introduce He gas, it is possible to inject drier He gas into the internal space between the inner cover 22 and the base 21e.

[0134] According to the magnetic disk device 30 of the second embodiment, the case 310 of the desiccant assembly 300 has a plurality of flow paths 312 extending radially from a position directly below the vent 222 of the inner cover 22, and the vent 313 on the top surface of the case 310 is connected to the end of each of the plurality of flow paths 312. This makes it possible to reduce the inflow speed of outside air flowing into the desiccant assembly 300 through the vent 222 of the inner cover 22, and to suppress a rapid moisture absorption reaction of the desiccant 340 due to the outside air.

[0135] The magnetic disk device 30 of the second embodiment further includes a seal 225 that airtightly closes the vent 222 to which the desiccant assembly 300 is connected. This allows the interior of the housing of the magnetic disk device 30 to be sealed, and prevents the internal desiccant 340 from being continuously exposed to the atmosphere.

[0136] According to the magnetic disk device 30 of the second embodiment, the needle 216e is provided on the FPC plate 215 disposed on the base 21e. This makes it possible to mount the components required for opening the desiccant assembly 300 in the limited space within the base 21e. Furthermore, since the area within the base 21e where the FPC plate 215 is installed has relatively ample space, it is easy to ensure a storage space for the desiccant assembly 300 attached to the inner cover 22.

[0137] According to the magnetic disk device 30 of the second embodiment, the sealing film 320 has a thin portion 321 that is processed to be thinner than other portions at the portion where the needle 216e penetrates. This allows the sealing film 320 to be easily broken by the needle 216e.

[0138] The sealing film 120 of the desiccant assembly 100 of the first embodiment may also be provided with a thin portion, like the sealing film 320 of the second embodiment.

[0139] In addition, the magnetic disk device 30 of the second embodiment has the same effects as the magnetic disk device 10 of the first embodiment described above.

[0140] (Variation 1) Next, a magnetic disk drive according to a first modification of the second embodiment will be described with reference to Figure 11. In the magnetic disk drive according to the first modification, a needle 216 is provided at a different location from that of the second embodiment.

[0141] 11 is a schematic diagram showing an example of a needle 216 included in a magnetic disk device according to Modification 1 of Embodiment 2. In the following drawings, the same components as those in the above-described Embodiment 2 are denoted by the same reference numerals, and their description may be omitted.

[0142] 11, in the magnetic disk device of Modification 1, similarly to the above-described Embodiment 1, needles 216 are provided on the base 21. Also, the FPC plate 215a of Modification 1 has through holes 15th for passing the needles 216 provided on the base 21.

[0143] According to the magnetic disk device of the first modification, by providing the needle 216 on the base 21, the same effects as those of the magnetic disk device 30 of the second embodiment described above can be achieved.

[0144] The desiccant assembly 100 of the first embodiment described above may be placed on an FPC plate that supports the FPC 18, and the needle 216 provided on the base 21 may serve as an opening mechanism for the desiccant assembly 100 by penetrating the FPC plate 215a of the first modified example described above and protruding into the housing 20. This allows further space-saving in the magnetic disk device 10 of the first embodiment.

[0145] Furthermore, as in the second embodiment, the needle 216e provided on the upper surface of the FPC plate 215 can also be applied as the opening mechanism of the desiccant assembly 100 of the first embodiment.

[0146] (Variation 2) Next, a desiccant assembly 300a according to a second modification of the second embodiment will be described with reference to Fig. 12. The desiccant assembly 300a according to the second modification differs from the desiccant assembly 300 according to the second embodiment in that it also has a filter 315 at its lower end.

[0147] Fig. 12 is a schematic diagram showing an example of the configuration of a desiccant assembly 300a according to Modification 2 of Embodiment 2. More specifically, Fig. 12(a) is a perspective view of the desiccant assembly 300a of Modification 2 viewed from below, and Fig. 12(b) is a cross-sectional view showing the desiccant assembly 300a of Modification 2 mounted in a magnetic disk drive.

[0148] In the following drawings, the same components as those in the second embodiment are denoted by the same reference numerals, and the description thereof may be omitted.

[0149] 12(a), the desiccant assembly 300a of the second modification includes a filter 315 on the bottom surface of the case 310. The filter 315 is provided in a ring shape that surrounds the outer edge of the bottom surface of the case 310 and protrudes from the bottom surface of the case 310. The height that the filter 315 protrudes from the bottom surface of the case 310 is approximately the same as the height of the gap that occurs between the bottom surface of the desiccant assembly 300a and the top surface of the FPC plate 215 when the desiccant assembly 300a is mounted in, for example, a magnetic disk drive.

[0150] The filter 315, like the filter 330, is a membrane filter made of, for example, PTFE, and is configured to be permeable to air, gases such as He, and moisture in gases.

[0151] 12(b), when the desiccant assembly 300a of the second modification is mounted in the magnetic disk drive, the filter 315 protruding from the bottom surface of the case 310 is in contact with the top surface of the FPC plate 215. The annular filter 315 is in contact with the top surface of the FPC plate 215, so that the space between the bottom surface of the case 310 and the top surface of the FPC plate 215 is shielded by the filter 315 from the rest of the internal space of the housing.

[0152] The filter 315 of the second modification is an example of a shielding filter that shields the space between the case 310 and the base 21e from the internal space of the housing.

[0153] When needle 216e penetrates sealing film 320 provided on the underside of case 310, dust C and the like may be generated from the broken sealing film 320. The above-mentioned filter 315 prevents dust C scattered in the space between the underside of case 310 and the upper surface of FPC plate 215 from scattering into the internal space of the housing. However, filter 315 allows air, gases such as He, and moisture in gases to pass through, and therefore does not interfere with moisture absorption management within the housing by desiccant 340.

[0154] According to the magnetic disk drive of Modification 2, the desiccant assembly 300a further includes a filter 315 that surrounds the outer periphery of the surface of the case 310 that faces the base 21e and shields the space between the case 310 and the base 21e from the internal space of the housing. This makes it possible to prevent dust C and the like that is generated from the sealing film 320 broken by the needle 216e, for example, from scattering into the space within the housing.

[0155] In addition, the magnetic disk device of the second modification provides the same effects as the magnetic disk device 30 of the second embodiment described above.

[0156] (Variation 3) Next, a magnetic disk device according to a third modification of the second embodiment will be described with reference to Figure 13. The magnetic disk device according to the third modification is provided with any one of needles 216a to 216c having a shape different from that of the second embodiment described above.

[0157] 13 is a schematic diagram showing some examples of needles 216a to 216c included in a magnetic disk device according to Modification 3 of Embodiment 2. In the following drawings, the same reference numerals are used to designate the same components as those in the above-described Embodiment 2, and the description thereof may be omitted.

[0158] 13(a), the needle 216a has a plurality of recesses 217a at its upper end. The recesses 217a are separated from one another by ridges that extend radially from the center of the upper end. The depths of the recesses 217a are adjusted so that they are recessed to a position below the sealing film 320 after the needle 216a penetrates it. In other words, after the needle 216a penetrates the sealing film 320, the bottoms of the recesses 217a are located below the sealing film 320.

[0159] This allows the atmosphere inside the housing to communicate with space 310r in case 310 through not only the gap between needle 216a and sealing film 320 but also through recess 217a at the upper end of needle 216a. Even if torn sealing film 320 wraps around needle 216a and blocks the gap, communication between the inside of the housing and space 310r in case 310 is ensured through recess 217a at the upper end of needle 216a.

[0160] 13(b), the needle 216b has a plurality of grooves 217b extending radially from the sharp tip and downward along the sidewall of the needle 216b, at least to a position below the sealing film 320 after the needle 216b has penetrated.

[0161] This allows the atmosphere inside the housing to communicate with space 310r in case 310 through groove 217b on the side wall of needle 216b, in addition to through the gap between needle 216b and sealing film 320. Even if torn sealing film 320 wraps around needle 216b and blocks the gap, communication between the inside of the housing and space 310r in case 310 is ensured through groove 217b on the side wall of needle 216b.

[0162] 13(c), needle 216c has a through-hole 217c that penetrates from the sharp tip through the interior of needle 216c in the extension direction of needle 216c. The FPC plate also has a groove 218c at the lower end of needle 216c that is connected to through-hole 217c inside needle 216c and extends outward from the lower end of needle 216c.

[0163] This allows the atmosphere inside the housing to communicate with the space 310r inside the case 310 not only through the gap in the sealing film 320 that occurs between the needle 216c and the sealing film 320, but also through the through-hole 217c that penetrates the needle 216c and the groove 218c on the top surface of the FPC plate.

[0164] According to the magnetic disk device of the third modification, the needle 216a has a recess 217a at the top end thereof, which is recessed to a position below the sealing film 320 through which the needle 216a penetrates.

[0165] Alternatively, the needle 216b has a groove 217b extending in the vertical direction of the sealing film 320 through which the needle 216b penetrates.

[0166] Alternatively, the needle 216c has a through hole 217c that penetrates the needle 216c in the direction of extension of the needle 216c, and the FPC plate has a groove 218c in its side wall that is connected to the through hole 217c of the needle 216c and extends outward from the lower end of the needle 216c.

[0167] This creates larger gaps in the sealing film 320, accelerating the moisture absorption reaction inside the housing by the desiccant 340. Furthermore, the recess 217a of the needle 216a or the groove 217b of the needle 216b makes the sealing film 320 even more likely to break.

[0168] In addition, as an opening mechanism for the desiccant assembly 300 of the above-mentioned embodiment 2, a needle 216d having an extension portion 219ax extending through the sealing film 320 and a piercing portion 219tp provided at the upper end of the needle 216d, at least a portion of which has a cross-sectional area larger than that of the extension portion 219ax, may be used, as in variant example 2 of the above-mentioned embodiment 1.

[0169] In addition, the magnetic disk device of the third modification provides the same effects as the magnetic disk device 30 of the second embodiment.

[0170] It should be noted that any one of the needles 216a to 216c of the third modified example can be applied as the opening mechanism of the desiccant assembly 100 of the first embodiment.

[0171] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0172] 10, 30... magnetic disk device, 12... magnetic disk, 20... housing, 21, 21d, 21e... base, 22... inner cover, 23... outer cover, 100, 100a, 300, 300a... desiccant assembly, 110, 110a, 310... case, 110f, 110r, 310f, 310r... space, 113t... inner lid, 120, 120a, 320... sealing Membrane, 130, 315, 330...filter, 140, 340...desiccant, 215, 215a...FPC plate, 216, 216a, 216b, 216c, 216d, 216e...needle, 217a...recess, 217b, 218c...groove, 217c...through hole, 219ax...extension portion, 219tp...piercing portion, 222...vent, 312...flow path, 313...vent.

Claims

1. a housing formed by combining a base and a cover and sealing the housing airtightly; a magnetic disk housed in the housing; a needle protruding upward into the internal space of the housing; a desiccant assembly provided on the cover so as to face the base at a predetermined distance from the base, The desiccant assembly includes: a case having an opening on a surface facing the base; a sealing film provided in the opening; a dividing filter that divides the space inside the case into a first chamber and a second chamber including the opening; a desiccant filled in the first chamber; The second chamber comprises: The needle penetrates the sealing film, thereby communicating with the internal space of the housing. Magnetic disk device.

2. The splitting filter is The cover extends in a direction intersecting the inner surface of the cover and divides the space within the case in a direction along the inner surface of the cover, The first and second chambers include: are arranged side by side in a direction along the inner surface of the cover, 2. The magnetic disk drive according to claim 1.

3. The splitting filter is the cover extends in a direction along the inner surface of the cover and divides the space within the case in a direction intersecting the inner surface of the cover; The first chamber comprises: disposed between the second chamber and the cover; 2. The magnetic disk drive according to claim 1.

4. The cover is a first vent opening extending through the cover; The case is a second vent port connecting the first vent port and the first chamber; 4. The magnetic disk drive according to claim 3.

5. The case is a plurality of flow paths extending radially from a position directly below the first vent hole; The second vent port is a plurality of second vents respectively connected to ends of the plurality of flow paths; 5. The magnetic disk drive according to claim 4.

6. further comprising a seal that airtightly closes the first vent opening; 5. The magnetic disk drive according to claim 4.

7. The desiccant assembly includes: a shielding filter surrounding an outer periphery of a surface of the case facing the base and shielding a space between the case and the base from an internal space of the housing; 4. The magnetic disk drive according to claim 3.

8. The sealing film is A thin-walled portion is formed at a portion through which the needle penetrates, the thin-walled portion being thinner than other portions.

2. The magnetic disk drive according to claim 1.

9. The needle provided on the inner surface of the base, 2. The magnetic disk drive according to claim 1.

10. The needle The FPC plate disposed on the base penetrates the FPC plate and protrudes into the internal space of the housing.

10. The magnetic disk drive according to claim 9.

11. The needle provided on an FPC plate disposed on the base, 2. The magnetic disk drive according to claim 1.

12. The upper end of the needle is located within the second chamber, The needle a through-hole that passes through the needle in the extension direction of the needle; The FPC plate is a groove connected to the through hole of the needle and extending outward from the lower end of the needle; The magnetic disk drive according to claim 11.

13. The upper end of the needle is located within the second chamber, The needle a recess at the upper end portion that is recessed to a position below the sealing film through which the needle penetrates; 2. The magnetic disk drive according to claim 1.

14. The upper end of the needle is located within the second chamber, The needle a groove extending in the vertical direction of the sealing film and through which the needle penetrates, on a side wall; 2. The magnetic disk drive according to claim 1.

15. The upper end of the needle is located within the second chamber, The needle an extension portion extending through the sealing film; a piercing portion provided at the upper end of the needle, at least a portion of which has a larger cross-sectional area than the extension portion; 2. The magnetic disk drive according to claim 1.

16. The internal space of the housing is filled with a gas having a density lower than that of air.

2. The magnetic disk drive according to claim 1.

17. a housing formed by combining a base and a cover and sealing the housing airtightly; a magnetic disk housed in the housing; a needle protruding upward into the internal space of the housing; a desiccant assembly provided on the cover so as to face the base at a predetermined distance from the base, The desiccant assembly includes: a case having an opening on a surface facing the base; an inner lid disposed above the opening; a sealing film pressed against a surface of the inner lid facing the opening; a dividing filter that divides the space inside the case into a first chamber and a second chamber including the opening, the first chamber and the second chamber being aligned along the inner surface of the cover; a desiccant filled in the first chamber; The needle The inner cover is inserted into the second chamber through the opening and abuts against a lower surface of the inner cover via the sealing membrane. Magnetic disk device.

18. placing a magnetic disk within a base from which the needle protrudes; On a surface of the cover provided with the ventilation hole facing the base, a case having an opening on a surface facing the base; a sealing film covering the opening; a dividing filter that divides the space inside the case into a first chamber and a second chamber including the opening; a desiccant filled in the first chamber; a desiccant assembly having: attaching the cover to which the desiccant assembly is attached, over the base on which the magnetic disk is placed; injecting a gas having a density lower than air into an internal space defined by the base and the cover through the vent hole of the cover, and combining the base and the cover to form an airtightly closed housing; Attaching the cover to the base includes: placing the base and the cover on top of each other, and abutting the needle protruding upward into the internal space between the base and the cover against the sealing film, and removing at least a portion of the sealing film from the opening with the needle, thereby communicating the second chamber with the internal space of the housing; and disposing the desiccant assembly facing the base at a predetermined distance from the base. A method for manufacturing a magnetic disk device.

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