Miscellaneous Part Models

Special Part models are available for use under the Miscellaneous Category for additional failure rate modeling options: Arrhenius and Test Data Extrapolation. 

Arrhenius Part Model Equation

The failure rate for the Arrhenius model is computed by the equation (user entered data in bold):

Failure Rate = A * e^(-E/(K*T))

Where:

A = K factor

E = Activation energy in eV

K = Boltzmann’s constant (8.617342E-5)

T = Temperature in °Kelvin (Note: Enter temperatures in °Celsius, Relyence will convert the temperature values to °Kelvin as needed.)

Test Data Extrapolation Part Model Equation

The failure rate for the Test Data Extrapolation model is computed by the equation (user entered data in bold):

Failure Rate = Chi2(a,b) / (2 * Number of Test Devices * Number of Test Hours * AF)

Note: Total Device Test Hours (Number of Test Devices * Number of Test Hours) can be entered directly

Where

Chi2 (a,b) = Inverse Chi-squared value where p-value = a and b degrees of freedom

Where:

a (based on Confidence Type): for Upper Bound = (Confidence Level / 100), for Lower Bound = 1 – (Confidence Level / 100)

b = 2 * (Number of Failures + 1)

AF = Acceleration Factor:

AF  = e ^{(E/K) * (( 1/Operating Temperature) – (1/Burn-in Temperature))}

Where

E = Activation energy in eV

K = Boltzmann’s constant (8.617342E-5)

All temperatures are in °Kelvin (Note: Enter temperatures in °Celsius, Relyence will convert the temperature values to °Kelvin as needed.)