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• #43 Raymond félisten GoldhandRent #42

  Új Válasz 2019-07-01 14:03:42 #43

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  Raymond

  félisten

  válasz GoldhandRent #42 üzenetére

  Most neztem hogy volt egy nagyon jo hozzaszolas az egyik hirhez errol, van benne par erdekes technikai reszlet is:

  If you're wondering how they lose $600M of stuff in just 13 minutes, I do vacuum engineering work (as one of the hats).

  Generally a setup like this is miles and miles of 'robots'. Not humanoid, but hexagonal with a chamber on each side. Each chamber exposes the wafer to things to build it up (gold), things to etch it, things to cure it. You roll up some wafers, the robot in the center moves one into chamber 1, does a process, then moves it from 1 to 2 and puts a new one in 1, etc, till all of the wafers have gone through the station and are ready for another combined process at the next station.

  Critically a lot of these processes are done at low vacuum (like 10 mTorr) and often with toxic gases or worse, pyrophoric gasses that explode on contact with normal air, like silane. Everything is closely timed, and you have to carefully maintain 1) the pressure of the chamber, 2) the rate of incoming substance(s). If you cure the wafers for only 3 minutes instead of 5, you lost the wafer. Now into this happy little juggling act you throw a power loss.

  *Honestly, it doesn't matter whether you lost if for 13 minutes or 13 seconds, you're done.*

  Your CDGs that measure pressure generally take two hours to get back to correct internal temperature, so they're reading wrong. That doesn't really matter anyhow because your valves failed and you either put not enough gas into the chamber or way too much. If you put way too much in now your chamber is contaminated. And your vacuum pumps all failed, so you lost pressure control. The turbo pumps spin at 75000 RPM and can't handle any amount of thick gas, so maybe you bombed them (shattered the fans). The computers controlling these don't like being hard powered down.

  Worse, and this is low probability and means you designed something wrong, but if you got too much silane and it contacted air because your pumps are down, maybe your robot caught on fire. Probably not, but either way you have to check all your turbos, open up all your robots, remove the destroyed wafers, clean your chambers. Oh, and now you need to recover all those process computers.

  Nightmare scenario.

  Privat velemeny - keretik nem megkovezni...

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