On the standardisation of thermal characterisation of LEDs Part II: Problem definition and potential solutions

Nowadays the demand for thermal standards for power LEDs is increasing. On the one hand metrics for fair comparison of competing products are needed, on the other hand, designers of power LED based applications demand reliable and meaningful data for their daily work. Todaypsilas data sheet information does hardly meet any of these requirements. Part I compares the current situation in the LED world with the situation in the IC world over twenty years ago, observes that much can be learned from the progress achieved, and concludes with a proposal for action. Part II addresses thermal issues that are specific to light emitting diodes (in fact, also semiconductor devices), the drawbacks of the current situation with respect to the information in the data sheets, and emphasises the need for electro-thermal models.