Hermetically-sealed disk drive device with flow amount adjuster and low-density gas sealed therein
View Patent ↗In a disk drive device having a double cover structure with low-density gas enclosed therein, embodiments of the present invention help to securely perform leak inspection on an outer cover and to prevent defects caused in joining the outer cover. According to one embodiment, a hard disk drive (HDD) comprises a flow amount adjuster on a base-facing side of its inner cover. Helium gas in an enclosure goes out through a ventilation hole via diffusion channel of a flow amount adjuster. The emitted helium gas remains in the space between the inner cover and an outer cover. This achieves easier detection of the leakage of helium gas from the joining section of the outer cover and prevention of emission of too much helium gas from the enclosure.
1. A disk drive device comprising:
a disk;
a motor for rotating the disk;
a moving mechanism for supporting and moving a head; and
an enclosure for enclosing the disk, the motor, the head, and the moving mechanism, and for hermetically containing gas comprising a lower density than air, the enclosure comprising:
a base;
a primary cover fixed to the base, the primary cover including a ventilation hole;
a flow amount adjuster for reducing a flow amount of gas which passes through the ventilation hole, wherein said flow amount adjuster is substantially C-shaped and is disposed directly over said disk, the flow amount adjuster comprising:
a first adhesive layer bonded to a disk-facing side of the primary cover, and including a diffusion channel formed in the first adhesive layer, wherein a first end of said diffusion channel is disposed proximate a first end of said first adhesive layer and a second end of said diffusion channel is disposed proximate a second end of said first adhesive layer, wherein said first adhesive layer is substantially C-shaped;
a second adhesive layer,
a filter membrane to suppress intrusion of dust, and
a moisture absorber to absorb moisture in the gas passing through the diffusion channel,
wherein the filter membrane and the moisture absorber are bonded to the second adhesive layer, and a space from said first end of the diffusion channel to said second end of the diffusion channel is defined by the first adhesive layer, the second adhesive layer and the primary cover;
a secondary cover disposed so as to cover the primary cover, the secondary cover joined to the base, and sealing the primary cover inside of the enclosure and wherein the diffusion channel is formed on a disk-facing side of the primary cover, and is connected to the ventilation hole; and
a third adhesive layer disposed between said primary cover and said secondary cover, wherein said third adhesive layer comprises:
a second channel, wherein said gas travels through said second channel to a space between a periphery of said third adhesive layer and a joining of said primary cover and said secondary cover.
2. The disk drive device according to the claim 1 , wherein pressure inside the enclosure formed by the primary cover and the base is higher than air pressure until a completion of joining the secondary cover.
3. The disk drive device according to the claim 2 , wherein an amount of low-density gas emitted through the ventilation hole and the flow amount adjuster until a completion of joining the secondary cover is more than a volume of a space between the secondary cover and the primary cover.