Disk device and method of manufacturing disk device
According to one embodiment, a disk device includes a disk-shaped recording medium, a head which processes data on the recording medium, and a housing accommodating the recording medium and the head. The housing includes a base with a side wall, and a cover having a welded portion welded to the side wall by laser welding. The welded portion includes a first welded portion welded to a first region of the side wall and having weld beads with a first shape, and a second welded portion welded to a second region of the side wall and having welded beads with a second shape different from the first shape.
1. A method of manufacturing a disk device, the method comprising:
placing a recording medium in a base of a housing;
fixing an inner cover onto the base to close an opening of the base;
placing an outer cover on the base to overlay the inner cover; and
welding a peripheral portion of the outer cover to the base from a point around to the point while controlling a welding condition depending on a section of the peripheral portion, the welding comprising welding a part of the peripheral portion of the outer cover to the base under a first welding condition, and
welding another part of the peripheral portion of the outer cover to the base under a second welding condition different from the first welding condition.
2. The method of claim 1 , further comprising:
exhausting the housing through a vent of the outer cover, and
filling the housing with a gas having a density lower than that of air after the welding.
3. A method of manufacturing a disk device, the method comprising:
placing a recording medium in a base of a housing;
fixing an inner cover onto the base to close an opening of the base;
placing an outer cover on the base to overlay the inner cover; and welding a peripheral portion of the outer cover to the base from a point around to the point while controlling a welding condition depending on a section of the peripheral portion, the welding including a laser welding which comprises welding a part of the peripheral portion of the cover to the base by a laser beam under a first laser irradiation condition, and
welding another part of the peripheral portion of the cover to the base by a laser beam under a second laser irradiation condition different from the first laser irradiation condition.
4. The method of claim 3 , wherein
under the first laser irradiation condition, the laser beam is irradiated at a first laser output, and
under the second laser irradiation condition, the laser beam is irradiated at a second laser output different from the first laser output.
5. The method of claim 3 , wherein
under the first laser irradiation condition, the laser beam is irradiated continuously, and
under the second laser irradiation condition, the laser beam is irradiated in pulses.
6. The method of claim 3 , wherein
under the first laser irradiation condition, the laser beam is irradiated at a first scanning speed, and
under the second laser irradiation condition, the laser beam is irradiated at a second scanning speed different from the first scanning speed.
7. The method of claim 3 , wherein
under the first laser irradiation condition, the laser beam is irradiated in pulses at a first pulse frequency, and
under the second laser irradiation condition, the laser beam is irradiated in pulses at a second pulse frequency different from the first pulse frequency.
8. The method of claim 3 , wherein
under the first laser irradiation condition, the laser beam is irradiated in pulses at a first pulse pitch, and
under the second laser irradiation condition, the laser beam is irradiated in pulses at a second pulse pitch different from the first pulse pitch.
9. The method of claim 3 , wherein
under the first laser irradiation condition, the laser beam is irradiated in pulses by a first beam spot diameter, and
under the second laser irradiation condition, the laser beam is irradiated in pulses at a second beam spot diameter less than the first pulse spot diameter.
10. The method of claim 3 , wherein
under the first laser irradiation condition, the laser beam is irradiated in pulses by a beam spot of a first focal depth, and
under the second laser irradiation condition, the laser beam is irradiated in pulses by a beam spot having a second focal depth less than the first focal depth.
11. The method of claim 3 , wherein
under the first laser irradiation condition, the laser beam is irradiated continuously at a first scanning speed, and
under the second laser irradiation condition, the laser beam is irradiated continuously at a second scanning speed lower than the first scanning speed.
12. The method of claim 3 , wherein
under the first laser irradiation condition, a laser irradiated position is set at a center of the first region in a width direction, and
under the second laser irradiation condition, a laser irradiated position is set at a center of the second region in a width direction.
13. A method of manufacturing a disk device, the method comprising:
placing a recording medium in a base of a housing;
fixing an inner cover onto the base to close an opening of the base;
placing an outer cover on the base to overlay the inner cover; and
welding a peripheral portion of the outer cover to the base sequentially from a point around to the point while controlling a welding condition, the welding comprising welding a part of the peripheral portion of the outer cover to the base under a first welding condition, and
welding another part of the peripheral portion of the outer cover to the base under a second welding condition different from the first welding condition.