寿命测试计算方法表

2000

57525 5.99128.898155426.430655405测试项目

计算公式：MTBF =2* T*SS*AF/confidence level

a.AF = Temperature acceleration Factor (Arr model)

Ts = the test temperature in °K = 85°C + 273

Tu= the reference temperature, or typical operating temperature in °K = 25°C+273k = Boltzmann’s Co nstant = 8.6 * 10-5 eV/°K

Ea = Activation Energy (in eV) = 0.6

AF = the acceleration factor : 50.06

b. Confidence level:

X2(1-a),2(r+1)is degree of freedom2(+1) chi-square Distribution 1-a quantif fractile；if 0pcs failure Confidence level:5.991Confidence level95%；r:failure quantity

CHINV(1-a,2(r+1))

if 0pcs failure Confidence level:5.991

if 1pcs failure Confidence level:9.488

if 2pcs failure Confidence level:12.592

c. Test time:

Tu=85℃ (Run time: 2011/8/13~2012/2/16)

1~4 PCS total test time(T1): 3965*4=15,860Hrs

5~12PCS total test time(T2): 3770*8=30,160Hrs

Tu=65℃（Run time: 2012/2/16/~2012/3/28

1~12 PCS total test time(T4): 950*12=11,407Hrs T\h

测试时间

SS 样本量TS 测试温度TU 参考温度Confidence level 可靠度AF 加速因子MTBF/年