Irradiance-based emissivity correction in infrared thermography for electronic applications

Abstract

This work analyzes, discusses, and proposes a solution to the problem of the emissivity correction present in infrared thermography when coatings with known emissivity cannot be deposited on the inspected surface. It is shown that the conventional technique based on two reference thermal images and the linearization of the blackbody radiation dependence on temperature is not a reliable and accurate solution when compared with the coating procedure. In this scenario, a new approach based on the direct processing of the output signal of the infrared camera (which is proportional to the detected irradiance) is proposed to obtain an accurate emissivity and surrounding reflections map, perfectly compensating the thermal maps. The results obtained have been validated using a module as a test vehicle containing two thermal test chips which incorporate embedded temperature sensors.

Efficiency determination of RF linear power amplifiers by steady-state temperature monitoring using built-in sensors

“…However, when relative measurements are performed, such as the ones indicated by Eq. (8), IR measurements do not depend on the emissivity or reflections of the sample surface [15].…”

“…9 shows the relative temperature variation at the whole IC surface when measured with the IR camera. In order to avoid emissivity cancelation [15], each pixel in the image is the result of the following operation:…”

Local non invasive study of SiC diodes with abnormal electrical behavior

“…Diodes D1 and D2 were coated with a high emissivity material to enhance the camera sensitivity [20] and to measure DTðr;r n ; t; f Þ, directly acquiring their |DT| and / s maps. In contrast, D3 and D4 were not coated and the lock-in amplitude |S DT | was acquired, which is proportional to the IR radiation emitted at the diode surface.…”

Design for reliability of solid state lighting systems

“…Convection and radiation have been prescribed on all surfaces exposed to air. The material infrared emissivity has been measured following the method reported in [4]. A zero stress temperature has been assumed for all materials considering manufacturing processes applicable for the LED board.…”