This paper shows a specific approach based on infrared (IR) thermography to face the challenging aspects of thermal measurement, mapping, and failure analysis on AlGaN/GaN high electron-mobility transistors (HEMTs) and MMICs. In the first part of this paper, IR thermography is used for the temperature measurement. Results are compared with 3D thermal simulations (ANSYS) to validate the thermal model of an 8x125pm AIGaN/GaN HEMT on SiC substrate. Measurements at different baseplate temperature are also performed to highlight the non-linearity of the thermal properties of materials. Then, correlations between the junction temperature and the life time are also discussed. In the second part, IR thermography is used for hot spot detection. The interest of the system for defect localization on AIGaN/GaN HEMT technology is presented through two case studies: a high temperature operating life test and a temperature humidity bias test.

The continuous miniaturization trends followed by a vast majority of electronic applications results in always denser PCBs (Printed Circuit Board) designs and PCBAs (Printed Circuit Board Assembly) with increasing solder joint densities. Current high-end designs feature high layer count sequential build-up PCBs with fine lines/spaces and numerous stacked filled microvias, as well as closely spaced BGA/QFN components with pitches down to 0.4mm. In recent years, several 3D packaging approaches have emerged to further increase system integration by enabling the stacking of several dies or packages. This has translated for example into the advent of highly integrated complex System in Package (SiP) modules, Package-on-Package (PoP) assemblies or chips embedded in PCBs [1]. From a failure analysis (FA) perspective, this deep technology evolution is setting extreme challenges for accurately locating a failure site, especially when destructive techniques are not desired. The few conventional non-destructive techniques like optical or x-ray inspection are now practically becoming useless for high density PCB designs. This paper reviews several advanced analysis techniques that could be used to overcome these limitations. It will be shown through several examples how three non-destructive methods usually dedicated to package analyses can be efficiently adapted to PCBs and PCBAs: • Scanning Acoustic Microscopy (SAM) • 3D X-ray Computed Tomography (CT) • Infrared Thermography A case study of a flex-rigid board FA is presented to show the efficiency of these three techniques over classical techniques. In this example, not only the defect localization has been possible, but also the defect characterization without using destructive analysis.

This paper focuses on infrared (IR) thermography capabilities on III-V components for thermal measurements applications and failure analysis (FA). The first part discusses the thermal mapping on InGaAs/AlGaAs PHEMT structure and compares IR thermal measurement with the well-known techniques as Raman and SThM. The second part discusses IR thermography on challenging FA for hot spot detection on the most popular type of capacitor for III-V MMICs as the metal-insulator-metal capacitor. It shows how IR thermography can easily localize very small pinholes in SiN, where liquid crystal and OBIRCH techniques are not well adapted.