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I'm interested in what design changes are required to support wildly different temperature tolerances. Take for example the following 3 chips:

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Nearly identical in form and function, package design, and performance, but one chip has an operating range of -55°C-125°C and another 0°C-70°C.

What changes does a manufacturer make to support these modified temperature ranges?

Derated MTBF? Different bonding wire materials? Or is the die design different entirely?

Ron Beyer
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The major difference is the moisture seal quality of a certain Sumitomo grade to freeze failures.

Baking and elevated wafer level screening is also done for high temp leakage currents.

Wafer fabrication processes and package level reliability are evaluated in a variety of ways that may include accelerated environmental test conditions.

Tony Stewart EE75
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  • So, if I get what you're saying... the lower temperature range is a moisture seal (I assume around the edges of the chip). I suppose that plays into the maximum RH throughout the temperature range... The upper end of the temperature range is still a little unclear to me... are you saying that it's the exact same die, but the quality of the wafer is higher and possibly processed differently? I understand the evaluation/testing side, I'm still not clear on what exactly changes to make it higher tolerance operating temps? – Ron Beyer Mar 07 '22 at 01:19
  • The wide temp requires more analog margin, moisture proof seals were once ceramic only, now special plastic. – Tony Stewart EE75 Mar 07 '22 at 01:31