An automated method for creating compact dynamic thermal models for in-situ prognostics of power electronics and power LED packages

• Main Authors: Poppe, Andras, Hantos, Gusztav, Hegedus, Janos, Ender, Ferenc
• Format: Conference Proceeding
• Language: English
• Subjects: Aging; Degradation; Electronic packaging thermal management; lifetime prognostics; Light emitting diodes; package compact thermal model; power LED; power semiconductor; Semiconductor device modeling; Thermal analysis; Thermal resistance
• ISSN: 2474-1523
• DOI: 10.1109/THERMINIC60375.2023.10325882

In their typical application domains, power electronics components (power MOSFETs, IGBTs) as well as high power LEDs are subjects to cyclic operation. The subsequent on-off cycles result in cyclic changes of the junction temperature, resulting in thermo-mechanical stresses at critical thermal interfaces such as the die-attach layer. Ultimately, in long-term, these stresses lead to the degradation of such interfaces, causing a continuous increase of the corresponding partial thermal resistances of the overall heat-flow path of such packaged devices. Further thermal interfaces on system level may also be subject of degradation as a result of ageing during the product lifespan.Over the last two decades, structure function analysis has proven to be a powerful tool in laboratory testing to detect the resulting failures such as die attach voiding or delamination. Combining power-cycling tests with thermal transient measurements resulted in commercial test equipment widely used nowadays in reliability testing of power electronics components, but as of today, no embedded, in-situ solution was published that is aimed at health-monitoring and prognostics purposes of such components during field operation. The aim of this paper is to present a method that could automatically generate time series of element values of a Cauer-type compact thermal model of the heat-flow path power electronics components and power LEDs during their operation. The series of partial thermal resistance values obtained this way allows a quasi-real-time analysis of the mission profile dependent degradation of the heat-flow path, allowing prognostics purposes, such as estimation of the remaining useful lifetime (RUL) from the perspective of the thermal properties.