Thermal imaging and measurement techniques for electronic materials and devices

The temperature stress occurring during electrical operation plays an important part in optimizing the performance and reliability of electronic devices. Thermal stress results from short transient processes (that can lead to critical junction temperatures within the chip) as well as from long-term cyclic stresses in a real system environment. The thermal characterization of materials, electronic components and modules by experiment represents an important contribution to quantifying and minimizing temperature stresses within the scope of a comprehensive approach to thermal management. This overview article describes the principles, characteristics and applications of(noncontacting) optical techniques that measure the absolute or relative temperatures of electronic devices or detect the thermal properties of materials. The range of techniques extends from conventional thermography (thermal imaging) via scanning laser probing (beam reflection and deflection techniques) up to near-field thermal microscopy. The presentation focuses on passive techniques that investigate the device under test in electrical operation (self-heating), but also take a look at photothermal methods that heat the specimen with a laser beam and analyze the thermal response (active techniques).