Delphi4LED — from measurements to standardized multi-domain compact models of LED: A new European R&D project for predictive and efficient multi-domain modeling and simulation of LEDs at all integration levels along the SSL supply chain

There are a few bottlenecks hampering efficient design of products on different integration levels of the SSL supply chain. One major issue is that data sheet information provided about packaged LEDs is usually insufficient and inconsistent among different LED vendors. Many data such as temperature sensitivity of different light output properties are provided to a limited extent only and usually by means of plots. Also, reported light output properties are typically rated for a junction temperature of 25 °C, which is obviously much below the junction temperature expected under real operating conditions. Even if “hot lumens” measured at a junction temperature of 85 °C this is not the actual operating temperature and there is little information about how such “hot lumen” tests are performed. The gap between and reported LED test data and actual operating conditions can be bridged by proper simulation models of LEDs and their environments. Such models should be accurate, hence capable of proper prediction of LED operation but simple enough to assure fast numerical simulations. However, LED integration do not get access to detailed LED information to perform those simulation at system level, thus perform reverse engineering which is time and cost consuming. A bridge, in the form of standardization, has to be established between the semiconductor industry and the LED component integrators. In order to achieve this, the following tools have to be provided: • Generic, multi-domain model of LED chips • Compact thermal model of the LED chips ‘environment (including the package and module assembly)’ Modeling interface towards the luminaire The goal of the project is to develop a standardized method to create multi-domain LED compact models from testing data.