11/15/2006 Assessed Failure Rate on ECX-31B 1. Assessed Failure Rate Assessed Failure Rate of ECS-.327-12.5-34B; 21.9 (Fit) Confidence Level at 60% Temperature at 25°C 2. Calculation Method (1) Results of Live Test at +85°C Model ECX-31B Sample Size 300 Testing Time 2,000 H (2) Assessed Failure Rate with Life Test at +85°C Failure Rate Total Testing Time 600,000 H Number of Failures 0 pc. Confidence Level at 60% λ=r/T Where r: Number of Failures T:Total Testing Time We presume with the upper failure rate because the number of failures is 0. λu=0.917/T =0.917/600,000 =1,528 (Fit) Confidence Level at 60%, r=0 Note: This formula can be found in JIS C5003-1974: General Test Pocedure of Failure Rate for Electronic Components. (3) Assesed Failure Rate at +25°C The Temperature Acceleration Factor is given by Arrehenius Law. Acceleration Factor αt=e (∆/k)*(1/T0-1/T1) = 69.6 Where: Activation Energy: ∆E=0.65 (eV) Boltzmann Constant: k=8.6173x10-5 (eV/K) Reference Temperature: To=25°C=298(K) Temp at Acceleration Condition: T1=85°C=358(K) Conclusion Assessed Failure Rate at 25°C λu=1,52/8(Fit)/69.6 =21.9(Fit) 1 1 0 5 E C S , I n c . I n t e r n a t i o n a l S o u t h R i d g e v i e w R o a d , O l a t h e K A N S A S 1 - 8 0 0 - 2 3 7 - 1 0 4 1 , F a x : 9 1 3 - 7 8 2 - 6 9 9 1 w w w . e c s x t a l . c o m 6 6 0 6 2