if helium is better, why not use a vacuum?
A gas provides a "bearing" for the heads to ride on as the disk spins below it.
The Race to Seal Helium HDDs (2021)
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Re: The Race to Seal Helium HDDs (2021)
#12Re: The Race to Seal Helium HDDs (2021)
#13if helium is better, why not use a vacuum?
Heads ride on cushion of gas, would instantly friction weld into platters in vacuum.
Re: The Race to Seal Helium HDDs (2021)
#14if helium is better, why not use a vacuum?
A gas provides a "bearing" for the heads to ride on as the disk spins below it.
Right you are, forgot about that completely! IIRC this is important to prevent a headcrash if the drive is jolted while in operation (of course within certain limits).
Re: The Race to Seal Helium HDDs (2021)
#15if helium is better, why not use a vacuum?
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Re: The Race to Seal Helium HDDs (2021)
#16Re: The Race to Seal Helium HDDs (2021)
#17Re: The Race to Seal Helium HDDs (2021)
#18At least two roads to Rome: HGST/WD and Toshiba use laser welding, Seagate uses friction-stir welding (https://en.wikipedia.org/wiki/Friction_stir_welding).
edit: the close up in the Wikipedia article actually is from a hard drive
Re: The Race to Seal Helium HDDs (2021)
#19"Helium is notoriously difficult to contain. Its atoms are some of the tiniest in the universe."
It's a good article, and I learned a lot, but every so often it reads like something an 8th grader would write the night before their paper is due.
Re: The Race to Seal Helium HDDs (2021)
#20if helium is better, why not use a vacuum?
vacuums tend to collapse on themselves, I think it might be more costly in structural elements to prevent that?
It is better to think of a vacuum within air to be similar to a bubble underwater.
Air is like water in other ways too. We slightly "float" in air by the weight of air we displace. e.g. 80kg person is approximately 80 litres (density of a body is 1.010 kg/litre). Weight of displaced air is approx 0.1 gram (1.2929 gram/litre). So the floating effect of air reduces your weight (not mass) by about 0.1%.