Experimental Technique

Abstract

In Sect. 3.1, a number of thermography and lock-in thermography approaches from literature are described and discussed, both steady-state and non-steady-state, showing the large variety of thermography measurement possibilities. Many of these systems are not called thermography but rather thermo-AFM, or photothermal or thermo-elastic investigations. But, in principle, they are all designed to measure lateral surface temperature distributions, and can be used to investigate also electronic components. At the end of this chapter, the figures of merit of different lock-in thermography systems are compared in terms of the pixel-related system noise density, defined in Sect. 2.5. In Sects. 3.2 to 3.4, the experimental techniques of three different proven, highly sensitive lock-in thermography approaches are described in more detail. Both the hardware solutions and the software-based data acquisition and display options of the different lock-in thermography systems are discussed.