I once got a Mostek logo burned into a fingertip doing that...
--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)
How funny.
I got myself a permanent "Rubber Powder Tattoo' under the skin of my finger by accidentally touching a moving, aged V-belt edge. It sliced me open like a surgeon's blade. I was unable to wash the rubber powder infusion out, so it healed in place, becoming a permanent 'pigmentation adjustment'. Probably loaded up with PCBs knowing my luck.
Then your finger was out of calibration. You should be able to sense the heat before you touch the chip. :)
"Lunar Lander" Upright Arcade video game by Cinematronics, 1979.
Your vertical velocity is important as you touch down.
The point is that the manufacturer's schematic symbols are universally
*ugly*. I wouldn't use them on a bet.As far as the user adding parts to their database, that only happens in a really small company (or a very independent lab in a larger one). There is no way a database admin for a large company is just going to take whatever they're given by a user. The schematic capture database isn't in the driver's seat, either.
Exactly. Add to that, the process feedback portion is supposed to be functional too. ISO-9000 isn't a bad system at all, though I've never seen it implemented in any sane (or useful) manner. "Lip service" is being nice.
...and then measuring the results, as a feedback to the process.
No, there is more to it than that. It certainly started out empirically, when the DoD started to pour money into improving the reliability of solid-state electronics. In those days, only the DoD could afford such things, and the DoD probably bought half of all such components. People knew from experience that hotter stuff failed sooner, so the first step was to do a lot of measurements. This yielded the observation that failure rates of electronic components followed the Arrhenius equation, and yielded the activation energy or more commonly energies. The implication is that the failure processes are chemical in some way. This also led to failure analysis of each failed component, which ultimately led to the specific mechanism. And so on, with an aggregate effort measured in the billions of dollars. Now, many decades later, most of the failure mechanisms are understood, and can be prevented. If it were not so, there would be no modern computers of cellphones or digital television and ...
But as for the original question about how long chips can tolerate overvoltage, the answer is typically microseconds, unless the chip is designed to break down gracefully (like a zener diode). The usual failure mechanism is that the hotter the material the lower the resistance so the current ends up all going through a single hot spot, which literally melts, permanently shorting the device.
Joe Gwinn
You are hard to talk to. As an engineer in a company of some 1500 employees, I would add the part to the schematic database. Purchasing would add their info to it and it could then be used by anyone in the company. I never said anything about the manufacturer's components.
But mostly I was referring to the fact that once the part has been used, regardless of the mechanism, samples in a prototype or a production run, it is in the company and has been entered into the systems, so it shows up internally for others to use. That doesn't matter what size the company is.
Rick
In lots of companies that I work with, IT departments, and company database admins, are already doing all they can to keep stuff from getting done. They sure shouldn't own a PCB library.
A couple of gigabuck companies that I could name (but won't) ask US for copies of their technical and purchasing docs. And they send us documents with identical revs and dates, but different numbers of pages.
-- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
Only by pig-headed morons.
Purchasing uses the engineering databases? Your company is out of control! It should be the other way around.
You don't buy components from a manufacturer? The discussion *did* include taking the manufacturer's data, which I replied that only an idiot would do such. They're universally *ugly*. You can continue down that thread if you want but perhaps you should learn to read, first.
How do you resolve conflicts? This is *NOT* as small of a problem as you pretend.
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