Advanced in situ characterization of TIM1 reliability

Innovative in situ Environmental Scanning Electron Microscope (ESEM) hot stage metrology was developed to understand packaging process and failure mechanisms through elevated temperature. For solder thermal interface materials (STIM), AuIn₂ intermetallic compound (IMC) spallation during indium melting is proposed to explain its formation mechanism correlated to STIM thermal degradation. For the first time, AuIn₂ IMC spallation is validated by direct observation of its dynamic behavior at elevated temperature using in situ ESEM hot stage metrology. In situ ESEM hot stage study also demonstrates that package dynamic warpage is a key contributor for corner delamination of polymer thermal interface materials (PTIM). It is found that the force applied with heatsink at the platform level helps to alleviate the risk of PTIM delamination. Application of in situ ESEM hot stage metrology to predicting package thermal performance and understanding package dynamic warpage induced failures are discussed.