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Cyanate-ester-based thermosetting die attach materials, commonly known as Low Temperature Die Attach (LTDA), are an innovation in hermetic die attach technology when it first emerged, due to their improved manufacturability, high decomposition temperature, and moisture gettering characteristics. This study investigated the behavior of LTDA under thermal and moisture conditioning. The total moisture gettering capacity of LTDA is considerable when compared to silver-epoxy paste. The LTDA exhibited 'physical' erosion during long-term exposure to environments more severe than 85 deg C and 85% RH. IR analysis confirmed the occurrence of water 'incorporation' into the LTDA structure, which increases with prolonged sample exposure. The IR spectra of the samples showed no major peak formation and changes indicative of significant structural change though. Die shear strength degrades quickly to critical level under harsh conditions (>85 deg C/85% RH). However, the die shear strength behavior at 85 deg C/60% RH revealed no reliability concerns even after 168 hours of exposure. The study's model equation predicted the time to failure under shop floor environment (25 deg C/55%RH) to be in the order of 10^6 hours.
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