Comment by bsder | Hacker News Reader

Comment by bsder | Hacker News Reader

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> You buy or make a thermal chamber and cycle release versions of your device before you ship one.

That is a total waste of time in a startup with a small number of units shipped.

A component behaving out of spec due to temperature excursions simply isn't that common nowadays. If my system is mostly ADC to digital to DAC (standard for robotics controllers), testing for temperature is a waste until I'm shipping significant volumes.

There is a video of one of the slightly famous YouTubers who has a high voltage thing that fails at the altitude of his lab. The manufacturer did check it for function at the elevation of Denver, but his lab is higher than that. There are limits to how much engineering effort you should put in until you get an actual failure. (Maybe someone can link the video as I can't remember it at this point.)

You can waste infinite engineering effort covering all possibilities. Or you can ship the thing and fix the failures. "Good engineering" is about balancing the two--you need to ship, but you don't want to have too many failures in the field either.

No, often components are dependent on the stress they are under. If you have inconsistent reflow, or lots of rework happening, then each device will behave differently due to thermal contractions.

Testing thermal performance is as simple as going to a restaurant down the street and asking if you can pay them $100 to borrow their walk-in fridge for an hour for cold, and leaving your device in a hot car for an hour for hot. It's also exactly the kind of thing you should be doing if you're selling an actual product to a customer instead of partnering with someone to test your prototype.

>A component behaving out of spec due to temperature excursions simply isn't that common nowadays.

You are right. People are commenting here as if the company didn't know what they were doing. I suspect there is more to the story then what has been shared in a tweet. My guess is that the deployment was done in a place with a temperature differential well outside the component specs/tests and so simply was not known/tested for.

Except that it isn't. They just proved it with their tweet. They wasted a ton of time and money on what they thought was the problem and what sounds like essentially a product recall.

A $5k temperature chamber running over night or weekend would have caught this.

If you specify an operating temperature range for your gadget, some testing at the extremes of that range is called for.

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