AN503: SCM5B Failure Rate Calculation and Prediction

Failure rate calculations for the SCM5B modules are derived from the MIL-HDBK-217E specification. The stress-analysis method is used at ground benign environment, 35°C temperature, and quality level of B-2 to D-1 depending on the part. Our specified humidity level is 95% RH noncondensing.

MODEL                                             FAILURES/10⁶ HRS                               MTBF (HRS)
SCM5B30/31/32/37/392-xx                          1.54                                                  650,000
SCM5B33-xx                                                 2.14                                                  468,000
SCM5B40/41-xx                                            1.46                                                  680,000
SCM5B38/39/42/43/49-xx                            1.35                                                  740,000
SCM5B34/35/36-xx                                      1.48                                                   675,000
SCM5B45-xx                                                 1.84                                                   545,000
SCM5B47-xx                                                 1.50                                                   670,000
SCMPB01, 05                                                1.83                                                   546,000
SCMPB02, 06                                                2.16                                                   463,000
SCMPB03                                                      0.19                                                5,150,000
SCMPB04                                                      0.23                                                4,430,000

Estimated actual failure rates are predicted to be much lower due to 100% powered burn-in for 48 hours at 85°C. The typical measured failure rate for the 5B modules is 0.34 failures per 106 hours (2,900,000 hours MTBF).