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Ceramic Column Grid Array packages have been increasing in use based on their
advantages such as high interconnect density, very good thermal and electrical performance,
compatibility with standard surface-mount packaging assembly processes, etc. CCGA packages
are used in space applications such as in logics and microprocessor functions,
telecommunications, flight avionics, payload electronics, etc. 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.
CCGA interconnect electronic package printed wiring boards (PWBs) of polyimide have been
assembled, inspected non-destructively and subsequently subjected to extreme temperature
thermal cycling to assess the reliability for future deep space, short and long-term, extreme
temperature missions. In this investigation, the employed temperature range covers from -185°C
to +125°C extreme thermal environments. The test hardware consists of two CCGA717 packages
with each package divided into four daisy-chained sections, for a total of eight daisy chains to be
monitored. The CCGA717 package is 33 mm × 33 mm with a 27×27 array of 80%/20% Pb/Sn
columns on a 1.27 mm pitch. The resistance of daisy-chained, CCGA interconnects were
continuously monitored as a function of thermal cycling. Electrical resistance measurements as a
function of thermal cycling are reported and the tests to date have shown significant change in
daisy chain resistance as a function of thermal cycling. The change in interconnect resistance
becomes more noticeable with increasing number of thermal cycles. This paper will describe the
experimental test results of CCGA testing under wide extreme temperatures. Standard Weibull
analysis tools were used to extract the Weibull parameters to understand the CCGA failures.
Optical inspection results clearly indicate that the solder joints of columns with the board and the
ceramic package have failed as a function of thermal cycling. The first failure was observed at
137th thermal cycle and 63.2% failures of daisy chains have occurred at about 664 thermal cycles.
The shape parameter extracted from Weibull plot was about 1.47 which indicates the failures
were related to failures occurred during the flat region or useful life region of standard bath tub
curve. Based on this experimental test data one can use the CCGAs for the temperature range
studied for ~100 thermal cycles (ΔT = 310°C, 5oC/minute, and 15 minutes dwell) with high
degree of confidence for high reliability space and other applications.
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