The final measure of reliability is actual performance in operating systems. Available data on system applications of LCCs on MIBs is limited. Table 7-2 lists the accumulated operating life data and pertinent environments for four Naval electronic systems. The length of operation extends to almost two years, with over 25 million module hours. There have been many more module failures observed than indicated, but they have not been associated with the LCC and MIB method of packaging and interconnection.
TABLE 7-2. SUMMARY OF OPERATING LIFE DATA
CALANDER TIME (HOURS)
3,000 to 8,500
100 to 13,500
* Does not include IC functional failures ** Two were MIB shorts at time of
Two of the MIB failures were shorts in copper thick
film MIBs detected at the time of installation. Another was a short in a
copper MIB occurring after extended operation. The existing data indicates a
higher level of reliability under field conditions for MIBs fabricated with
the noble metal thick film system.