Supplement: Power
The relationship between temperature and reliability in electronic systems
The reliability of electronic systems is paramount in ensuring their optimal performance and longevity. One of the most signifi cant factors affecting this reliability is temperature. As electronic components operate, they generate heat, and if not managed effectively, this heat can lead to premature failures and reduced system lifespans. In this article, RELEC delves into the intricate relationship between temperature and reliability, highlighting the profound effects of temperature on electronic components, particularly semiconductors and explores the origins of the rule that states that failure rates will double for a 10°C rise in temperature.
The Arrhenius equation and its implications
At the heart of understanding the temperature-reliability relationship is the Arrhenius equation, a fundamental formula in chemistry and physics that describes the temperature dependence of reaction rates. In the context of electronics, it can be used to predict the rate of failure or degradation of components based on temperature. A simplified version of the Arrhenius equation is:
Where: Rate is the failure rate or reaction rate. A is a pre-exponential factor. Ea is the activation energy or energy barrier that must be overcome for a specific failure to occur.
k is the Boltzmann constant. T is the absolute temperature (in Kelvin). The exponential term in the Arrhenius equation is pivotal in determining the temperature dependence of the failure rate. To discern the influence of a 10°C increase in temperature, we compare the failure rates at two temperatures: T & T+10 (where the 10 is in Kelvin, representing a 10°C increase).
26 December/January 2025 Components in Electronics
Using the Arrhenius equation, the ratio of the failure rates at these temperatures is:
This equation can be simplified to:
For our rule of thumb to be accurate, this ratio should be approximately 2, indicating that the failure rate doubles with a 10°C increase.
Typical activation energy ranges To determine the range of Ea values that satisfy this condition, one would need to solve the above equation for Ea given a specifi c initial temperature T and the desired ratio (2 in this case). The exact range of Ea values will vary based on T, but for many electronic components operating in typical ambient conditions (around 25°C or 298K), Ea values often fall within the range of 0.5 to 1.5 eV (electron volts) to make the rule of thumb approximately true with some common devices listed below.
Semiconductors: Silicon transistors and diodes: 0.6 to 0.7 eV
www.cieonline.co.uk
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68
