Common Problem
How to determine the service life of the product?
resolve
The durability of the product is determined by accelerating the test in the regular reliability test to determine the time equivalent to the service life of the product.
The acceleration test has voltage acceleration and temperature acceleration, and SII performs temperature acceleration test in accordance with Arrhenius mode.
The acceleration coefficient is calculated according to JEITA specification EIAJ4701 by the following calculation formula.
(Acceleration coefficient calculation formula) L=exp(Ea/kT2)/exp(Ea/kT1)
L: acceleration factor
Ea: Active energy
K: Boltzmann coefficient
T2: Actual service temperature (absolute temperature)
T1: Accelerated test temperature (absolute temperature)
Specifically, the following conditions are substituted into the formula.
Active energy 0.5 eV
Boltzmann coefficient 8.617× 10-5 eV/K
Actual operating temperature 40°C
The calculation shows that the acceleration coefficient of 125°C is 52 times that of 40°C.
Therefore,
1000 h→ equivalent to 5.9 years
2000 h→ equivalent to 11.8 years
By carrying out the above reliability test at 125°C for 2000 hours, it is possible to determine the service life of the product at the actual service temperature
Over 10 years.