Ceramic Column Grid Array (CCGA) packages have been increasing in use based on advantages such as high interconnect density, very good thermal and electrical performance, compatibility with standard surface-mount packaging assembly processes, etc. These packages are to be used in space applications such as logic and microprocessor functions, telecommunications, flight avionics, and payload electronics. As these packages tend to have less solder joint strain relief than leaded packages, the reliability of CCGA packages is very important for short- and long-term space missions. The assessment of reliability of CCGA 1752 Kyocera packages is of paramount importance to space applications.
Titan, Europa, asteroids, comets, Earth’s moon, and Mars (MER) Spirit and Opportunity and MSL Curiosity require operation of thermally uncontrolled hardware under extremely cold and hot temperatures with large diurnal temperature change from day to night. The planetary protection requires the hardware to be baked at +125 ºC for 72 hours, or as needed, to kill micro-bugs to avoid any biological contamination, especially for sample return missions. NASA-standard thermal cycling temperature range varies from -55 ºC to +100 ºC. Consequently, the present CCGA Kyocera package reliability research study encompasses the temperature range of -55 ºC ±10 ºC, to +125 ºC to cover various NASA deep space missions.
Based on the existing published data, there are no systematic CCGA reflow/rework processes and experimental test data available to assess the reliability of CCGA packages in extremely low and high temperatures such as those cited above. Therefore, this exploration describes the important experimental test results obtained in this extreme temperature range for deep space applications.
This research has reported the reliability study down to -55 ºC ±10 ºC, and up to +125 ºC. This is the novelty of the test results. Advanced 1752 CCGA Kyocera packaging interconnects technology test hardware objects have been subjected to temperature thermal cycles from -55 ºC ±10 ºC, to +125 ºC. X-ray inspection of CCGA packages was made before thermal cycling. No anomalous behavior and process problems were observed in the x-ray images. The change in resistance of the daisy-chained CCGA interconnects was measured as a function of increasing number of thermal cycles. Electrical continuity measurements of daisy-chains have shown no anomalies, even until 250 thermal cycles. Optical inspection of CCGA 1752 packages is yet to be made. No catastrophic failures have been observed yet in the electrical continuity results. Process qualification and assembly is required to optimize the CCGA assembly processes. Optical inspection of CCGA boards will be made after predetermined thermal cycles or after observing an anomaly in resistance measurements.