Combined Thermo-Reflectance and Thin-Film Coating in Near-Field Imaging of Chip-Package-PCB-Antenna Modules for Industrial-Testing and Failure Analysis

A holistic Near-Field (NF) Over-the-Air (OTA) testing solution for Chip-Package-PCB-Antenna modules based on combined thermo-reflectance and thin-film coating using Spin-Crossover (SCO) materials is proposed. The SCO coating process exhibits highly reliable thermometric performance (diffraction-limited sub-\mu m spatial, sub-\mu s temporal and 1°C thermal resolution), which stems to a large extent from the unprecedented quality of the vacuum-deposited thin films of the molecular complex used in this work. The resulting performance qualifies the SCO coating process, in terms of fabrication and switching endurance (surpassing 10
⁷
thermal cycles in ambient air), for industrial testing ensuring highly reproducible measurement results. The proposed NF sensing solutions are validated through several practical applications using front-end-modules (FEMs) manufactured in advanced GaN and FDSOI technologies co-designed with antenna-in-package (AiP) modules based on heterogeneous system-in-package (SiP) and WLCSP fan-in/fan-out integration assemblies.