If an IC is rated for an absolute maximum junction temperature of say 170 Celsius, obviously it is not recommended to operate there - but how drastically is product lifetime impacted if we are close, say operating at junction temperature of 160. How severely does the IC lifetime get shortened as we get closer to the maximum junction temperature ?


There are two rules of thumb when it comes to premature aging of electronics and temperature:

  1. Every 10°C above 25°C halves its life

  2. Every 15°C above 25°C halves its life.

The 10°C is derived from a certain application of Arrhenius' equation

\$ AF = e^{ \frac{E_a}{k}}(\frac{1}{T_{use}}- \frac{1}{T_{test}}) \$

The issue with this is the 10°C result was a very broad interpretation of the empirical results (no consideration was given to other failure modes).

MIL-HDBK-217 took into account field data and concluded that 15°C is a figure more applicable to practical usage


  • \$\begingroup\$ I think that Every 10°C above 25°C halves its life is related to chemistry. \$\endgroup\$ – Harry Svensson Nov 24 '18 at 11:27
  • \$\begingroup\$ I agree, this was then broadly applied. I have been looking into this recently wrt uprating. The problem is the mail is out of date \$\endgroup\$ – JonRB Nov 24 '18 at 13:16
  • 2
    \$\begingroup\$ And to just put a number to it. \$2^{\frac{160-25}{15}}=512\$. That means, if the device has a lifetime of 512 years at 25° C, then it will have a lifetime of 1 year at 160° C. \$\endgroup\$ – Harry Svensson Nov 25 '18 at 2:49

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