Recent Achievements and Approaches for Further Opimization of High Current Low Voltage Power Semiconductor Components

Achievable current density of low voltage power MOSFET components has increased signi cantly over the past years Those devices are mainly used in converters for automotive auxiliary drives or renewable energy The paper outlines state of the art technology and gives an outlook on further development taking into account the particular requirements of the aforementioned demanding applications Introduction Applications Power electronics has become an indispensable part of automotive electric system It supplies e g adjustable speed fans water or hydraulic pumps increasing use can be expected from the introduction of starter generator and V system with related units such as electromagnetic valve control Compared to known industrial power electronics in a similar power range of several Kilowatts the current levels in battery supplied automotive systems are high to achieve a compact power section consequently a high current density of the semiconductor devices is mandatory Operational conditions of converters frequently tempered by the coolant of the combustion engine are characterized by a wide temperature range with maximum heatsink temperature reaching some TS C This has an impact on component reliability which is requested to be extremely high for the time span of cars life expectancy thus leading to particularly demanding reliability criteria Cars powered by fuel cells show a link to other applications employing low voltage high current switches being related to renewable energies Fuel cell systems gain importance for storage and transportation of electrical energy especially generated from variable sources such as wind parks The output voltage of photovoltaic arrays depends on the number of series connected cells system con gurations using a boost converter to transform voltage of solar generator to a higher level e g to generate a mains like AC output with a subsequent inverter thus are frequently met E cient operation of converters in the eld of renewable energy is important leading to the requirement that the power semiconductor switches should operate with minimum losses High Current Low Voltage Power Semiconductor Components