The EEENET Workshop was held in Birmingham, U.K. on 18 September, 2002. Its main goal was to discus requirements and solutions for high temperature and high power devices.

The first report "Requirements presentation: high temperature/medium power devices" was presented by Peter Shrimpling from TRW. It outlined the necessity of high temperature semiconductor devices in avionics. Namely, the electronics operating in 200°C ambient is currently needed to replace the hydraulic amplifiers and actuators. Some applications fields are: elevator actuators, fuel pumps, starter generator, switching devices for engine control.

The list of semiconductor devices and circuits needed for these applications includes

- AC and DC to 3 phase converters from 20 to 100 kW (250 kW in starter generators) operating at ambient temperature > 110°C (> 60°C in elevator actuators); operating voltage of 350 V, frequency of 15 kHz;

- switching devices operating at ambient temperature > 110°C; operating voltage of 350 V, frequency of 15 kHz; in particular diodes with 50% duty cycle and minimum reverse recovery, peak current of 900 A (110 A at 50% duty cycle).

    Although  the ambient temperature of 110°C is not extremely high, high temperature devices are needed to reduce the mass, space and cost of heat dissipating systems. Operating voltage of 350 V is a result of compromise between the necessity of  mass and space decreasing and reliable insulating. At this operating voltage,  devices must have a breakdown voltage 600 - 900V. Avionics needs devices operating at frequency >100 kHz, lifetime > 100 kh (30k flight power cycles). It was mention also that avionics needs normally off devices to reduce the power consumption. More detailed information about SiC properties is necessary for high temperature circuits design, namely - plots of SiC thermal conductivity and expansion coefficient depending on temperature.

Requirements for high power devices were presented in second report given by Roger Bassett from Alstom (the Company specialises in three areas of activity in the UK: Power Generation; Power Transmission & Distribution; Rail Transport with a turnover approaching 2 billion euros). Alstom is leading the ESCAPEE project.  Currently,  silicon IGBT (1200/1700V - 2000 A), thyristors and GTO (4500 V - 4500 A) are used in high power electronics. It was pointed that  increasing of operating frequency allows to reduce the weight and space of facilities as well as operating temperature increasing allows to reduce weight, space and cost of heat sink.

The list of SiC devices which will find the application in high power electronics includes

- majority carrier devices: 3.5 kV Schottky diodes, MOSFET or MISiCFET with low  static and switching loss; f~100 kHz; operating current  50 - 2000 A; rating 25% real estate to Si; and

- bipolar devices: IGBT and p-i-n diodes with low loss; f~20 kHz; operating current 50 - 2000 A;  operating voltage 10 -25 kV; rating 25% real estate to Si.    

These reports were followed by discussion of SiC electronics current state and its capability to satisfy the requirements given in the reports. More detailed information about EEENET Workshop, its program and presentations slides are available for download at EEENET web site after the registration.