Former APPLICATION NOTES FOR MIL-PRF-49470 that are no longer applicable

The NPSL application notes for multilayer ceramic capacitors are being amended (May 2013) to reflect the following recommendations from a NASA Engineering & Safety Center (NESC) report ^[1] on the subject of low voltage failure phenomenon of ceramic capacitors:

R-1. NASA guidelines should be amended to remove any requirements to perform Humidity Steady-State Low Voltage (HSSLV) test as an add-on lot acceptance test for MIL QPL MLCCs.

R-3. NASA guidelines should be amended to remove restrictions on MLCCs rated at less than 100 V when used in low voltage applications.

Reference:

[1] “Multilayer Ceramic Capacitors (MLCC) –Low Voltage Failure (LVF) Phenomenon” NASA/TM-2010-216852, NESC-RP-07-056, October 2010, NASA Engineering and Safety Center (NESC)

Per the Recommendations of the Above Referenced NESC Report, the Following Application Notes Are No Longer Applicable to Parts Purchased in Accordance With MIL-PRF-49470

6)  For Level 2 applications at >=10 Vdc, "B" or "T" Level capacitors can be used in accordance with the type, value and failure rate guidelines shown in the tables.

7)  For Level 2 low voltage applications (< 10 Vdc), "B" level capacitor rated voltage should be at least 100 Vdc.  Alternatively, "B" level parts rated at less than 100 Vdc can be used if flight lots are subjected to lot sample testing per Group B Subgroup 4 of MIL-PRF-49470 (Humidity, Steady-State, Low Voltage).  "T" level parts can be used "as-is" because the Humidity, Steady-State, Low Voltage test is required on lot by lot basis.  Recommendations for performing this testing are prompted by low voltage failure concerns of multilayer ceramic capacitors.