Power Conversion With SiC Devices at Extremely High Ambient Temperatures

Abstract

This paper evaluates the capability of SiC power semiconductor devices, in particular JFET and Schottky barrier diodes (SBD) for application in high-temperature power electronics. SiC JFETs and SBDs were packaged in high temperature packages to measure the dc characteristics of these SiC devices at ambient temperatures ranging from 25 C (room temperature) up to 450 C. The results show that both devices can operate at 450 C, which is impossible for conventional Si devices, at the expense of significant derating. The current capability of the SiC SBD does not change with temperature, but as expected the JFET current decreases with rising temperatures. A 100V, 25W dc-dc converter is used as an example of a high-temperature power-electronics circuit because of circuit simplicity. The converter is designed and built in accordance with the static characteristics of the SiC devices measured under extremely high ambient temperatures, and then tested up to an ambient temperature of 400 C. The conduction loss of the SiC JFET increases slightly with increasing temperatures, as predicted from its dc characteristics, but its switching characteristics hardly change. Thus, SiC devices are well suited for operation in harsh temperature environments like aerospace and automotive applications. Index Terms-dc-dc converter circuit, device characterization, high temperature operation, packaging, silicon carbide (SiC) device. I. INTRODUCTION S ILICON CARBIDE (SiC) has several superior characteristics over silicon (Si) when used as a semiconductor material [1]-[6]. In particular, SiC semiconductor devices are expected

Improvement in Joint Reliability of SiC Power Devices by a Diffusion Barrier Between Au-Ge Solder and Cu/Ni(P)-Metalized Ceramic Substrates

“…[2][3][4][5][6][7] Because the application of SiC devices enables high-temperature operation of power converters, the cooling system can be reduced or eliminated. [8][9][10][11][12] As a result, the output power density of power converters can be significantly increased and their weight can be remarkably reduced. To realize high-temperature operation of SiC power devices, high-temperature packaging technologies are crucial.…”

Transient thermal analysis of packaged SiC SBDs for high temperature operation

“…The static and dynamic characteristics of the SiC devices over 400°C are reported in [1,2], and the successful operations of the SiC devices in power electric applications over 300°C are introduced in [3,4]. High temperature operation capability of SiC devices enables to increase power density and reduce a size of a power electronics system.…”

Temperature effects on the ruggedness of SiC Schottky diodes under surge current

“…However, this not only affects the reverse characteristics, but also modifies the device thermal behavior at forward bias [4]. In contrast with SBD's, whose positive temperature coefficient is dictated by the series resistance [5], JBS thermal behavior is predominated by the bipolar junction, which turns the overall temperature coefficient to negative [4]. Notice that both structures present Schottky and bipolar contacts parallel connected, whose current density balance is dictated by the device temperature [4], which could cause destructive local self-heating effects, especially in high temperature applications [6,7].…”