Reliability - HTRB Life

Central Semiconductor performs extensive reliability stress testing on a variety of products from our product portfolio. This data is collected in addition to our standard qualification test data for any new or changed product. Data noted herein is based on standard FIT rate calculations as detailed below:

(1) 60% Confidence Level. Accelerated testing.


The failure rate calculation based on a single life test is as follows:

λ = Failure Rate
TDH = Total Device Hours
AF= Acceleration Factor

The Accelleration Factor is calculated as follows:

Ea = Thermal Activation Energy
k =Boltzmann's Constant (8.63 x 10-5 eV)/K
Tuse= Use Temperature (°C + 273)
Tstress = Life test stress temperature (°C + 273)

The comprehensive failure rate is calculated as follow:

β = Number of distinct possible failure mechanisms
k= Number of life tests combined
xi = Number of failures for a given mechanism (1 = 1, 2, ... B)
TDHj = Total device hours of test time for life testj (j = 1, 2,... k)
AFij = Acceleration factor for appropriate failure mechanism (i = 1, 2,... k)
M = X2 ( , 2r +2) / 2
(where X2 = chi squre factor for 2r +2 degrees of freedom, r = total number of failures, ∝ = risk associated with CL between 0 and 1)

Reliability - Environmental

Typical results for all surface mount products: