SCALE HIAP Radiation Induced Reliability of Advanced Packaging

Graduate student Susan Huang of the University of Central Florida presented at the HIAP Lunch and Learn series.

The reliability of heterogeneously integrated gallium‑nitride (GaN) power devices is examined in the context of space‑grade advanced packaging. Because GaN offers high efficiency, elevated‑temperature operation, and compact form factors, its deployment in satellites, CubeSats, and lunar missions is rapidly expanding. However, the mechanical and radiation‑induced durability of the surrounding package often dictates overall system performance.
The investigation employs coupled multiphysics finite‑element simulations to reproduce extreme space conditions. ANSYS models thermal and structural responses during JDEX‑specified thermal cycling (‑55 °C to 150 °C, 50 °C min⁻¹ ramps, 5 min dwells) while tracking heat fluxes derived from EPC‑7014 GaNFET data. Stress fields are extracted from a single‑cycle analysis, converted to strain, and fed into the Coffin‑Manson fatigue law and Arrhenius‑based lifetime prediction to locate fatigue hotspots. Heavy‑ion transport is evaluated with SHRIM, simulating 23 GV xenon ions to assess energy deposition and shielding effectiveness across the multilayer stack comprising Al₂O₃ caps, SiC heat sinks, Ag thermal conduits, solder joints, and AlN substrates. The combined thermal‑structural‑radiation framework quantifies how coefficient‑of‑thermal‑expansion (CTE) mismatches drive interfacial stresses and potential delamination.
With this integrated model, learners can interpret simulation outputs to pinpoint stress concentrations that dominate failure mechanisms, analyze predicted fatigue life under realistic thermal cycling, and compare the shielding performance of alternative packaging materials against heavy‑ion exposure. By elucidating the role of CTE mismatches, they gain the ability to rationalize material selections and design strategies that enhance mechanical reliability of GaN devices for demanding space applications.