Overview of Thermal Characterization Techniques for Front-End Modules

Heating is a major bottleneck limiting the performance of RF devices, circuits and modules. We describe various methods to measure dynamic temperature distribution with resolution ranging from submicron in high-power high electronic transistors to millimeter and centimeter for circuits and boards. Infrared imaging, Raman and thermoreflectance methods and their applications are described. Full-field thermoreflectance thermal imaging can be used to characterize localized heating with sub-nanosecond and 10mK temperature resolutions. Results are presented for active devices such as GaN high electron mobility transistors and 3D heterogeneously integrated packages. We will also describe ultrafast methods based on an image blurring technique to calculate temperatures in circuits with thousands of active devices with simulation speeds that are orders of magnitude faster than those achievable by finite element methods.