Atsuyuki Hiruma

High Voltage and High Reliability Silicon-on-Insulator Power IC Technologies and Their Application to 750 V 4.5 A Micro-Inverter IC

We have successfully developed the record high blocking voltage of 750 V and the largest current capability of 4.5 A silicon-on-insulator (SOI) micro-inverter IC, which is made possible by the newly developed high voltage reliability technology and high-speed and low-dissipation extraction enhanced lateral insulated gate bipolar transistor (E2LIGBT). It has been found, for the first time, that the stable and reliable high blocking voltage of 760 V is assured by controlling the sheet-resistance of the polycrystalline silicon (poly-Si) layer of the scroll-shaped resistive field plate (SRFP). The high voltage and high reliability SOI power IC technology is expected as the key technology enabling 750 V 4.5 A micro-inverter IC for harsh applications such as automotive electronics.

A Novel Concept of High Voltage Auxiliaries and its Feasibility Study on Blower Motors

Hybrid/Electric Vehicles are expected to be one of the solutions for energy and environmental problems. Up to Now, low power automotive electronics have operated under a battery voltage of 12 V and a large current of more than 10 A. Because of this high current, the power electronic circuits cause substantial losses of power through wire harnesses, a DC/DC converter, semiconductors, and so on. In this paper, we have proposed a novel concept of high voltage auxiliaries, which replaces the 12 V loads with the high voltage loads driven directly by the high voltage battery. It is assured that the power efficiency of the high voltage test system is as high as 94 %, which is at least 10 % higher than that of conventional 12 V blower motor systems.

Loss reduction of lateral power diode on SOI substrate with trenched buried oxide layer

We have investigated the static and dynamic characteristics of high voltage lateral power diode (L-Diode) on silicon-oninsulator (SOI) substrate with planar / trenched buried oxide (Box) layer on the basis of device simulations. The conduction loss of the conventional L-Diode with planar Box layer is found to be reduced as a result of improving blocking capability by trenching the Box layer. In addition, the switching loss of the conventional L-Diode with planar Box layer, which stems from the second peak of the recovery current, is substantially reduced by adopting the trenched Box layer with suppression of the dynamic avalanche phenomenon.