Reliability Tests
Central Semiconductor performs extensive reliability stress testing on a variety of products from our product portfolio. This data is collected in addition to Central's standard qualification test data for any new or changed product.
Typical Results:
Reliability - FIT Rate (HTRB Life)
Data noted herein is based on standard FIT rate calculations as detailed below.
FIT rate calculations:
(1) 60% Confidence Level. Accelerated testing.
Formulas
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 square factor for 2r +2 degrees of freedom, r = total number of failures, ∝ = risk associated with CL between 0 and 1)
Package Reliability Summaries
Reliability Summaries for surface mount and through-hole package types can be found in the "Package Reliability" column of the tables below.