Transient Thermal Measurement of Electronic Components and Radiometric Characterization of LEDs

Abstract

Changing requirements for HEVs and EVs (e.g., for IGBTs) and automotive lighting with LEDs are forcing component manufacturers to re-think designs, moulding techniques or packaging strategies. These changes can result in new unknown thermal behaviours that could lead to bad thermal characteristics, delamination, increased thermal resistance and failure. This chapter will address how thermal and radiometric testing and measuring to obtain accurate thermal characterization helps to increase component reliability. We used thermal and radiometric testing and measuring software/hardware products (T3Ster and TERALED) to obtain thermal characterization data of various electronic semiconductor components such as LEDs, IGBTs, and different chips for thermal simulation to understand the thermal and radiometric behaviour of the design to be able to eliminate the risks of component failure before production and also to deliver accurate thermal characterization data for thermal simulations. We obtained high-accuracy thermal and radiometric measurement values of LEDs with repeatable results. The radiometric measurements of LEDs enable a detailed characterization of various parameters, such as radiant flux and color coordinates depending on current and temperature. With this information, we were able to make selections from different vendors after researching the aging effects on these components and therefore their quality. In other tests, we were able to determine component and assembly defects that can appear either because of aging or during manufacturing of the component or the assembly, which results in changes in thermal resistance and worsens the thermal behaviour. The transient thermal measurement of electrical components is limited to semiconductor-based electrical components and their assembled state on the PCB in its environment. This chapter shows a new technology with never before reached accuracy of thermal and radiometric coupled characterization of semiconductor components that helps ensure designing and manufacturing best-in-class components and high reliability systems that use such components. A detailed thermal characterization enables optimized thermal design of the system rather than over-designing the system for thermal performance. With additional LED radiometric characterization, the same can be done for optimal performance of LEDs. This is especially important in future EV and HEV where energy consumption is critical to a higher efficiency and extended range of the vehicles.

F2012-E14-013