Transient thermography using evanescent microwave microscope

Abstract

Very high spatial resolution thermography is of great importance in electronics, biology, and in many other situations where local variations in temperature are needed to study heat dissipation or to monitor metabolism rate which can be directly related to the heat production. Infrared imaging techniques probably are the best way of obtaining thermal maps of large structures. However, the spatial resolution of infrared imaging techniques is limited to a few 100 μm and their temperature resolution is usually around 0.1 K. Here we report on a new evanescent microwave method that is capable of mapping temperature distributions with ≈1 μm spatial resolution. The temperature sensitivity of this probe was better than 0.1 V/K with a minimum detectable signal of 0.01 K with a response time faster than 1 μs.