Thermal Management versus Full Isolation: Trade Off in Packaging Technologies of Modern SiC Diodes

Abstract

In this paper we compare the thermal behavior of identical SiC Schottky diodes mounted in i) a standard TO220 package (TO220) with non-isolated backside applying standard soft solder and diffusion solder die attach with ii) a so called FULLPAK TO220 package (TO220FP, only diffusion soldering). Depending on the solder technique the heat transport from the junction area of the SiC Schottky diode to the heat sink or to the package backside is improved for the diodes mounted via diffusion solder. For small chips this holds even for TO220FP in comparison to TO220 with standard solder. Simulations of the vertical temperature distribution after electrically heating with a half sine wave for 10ms up to 190W show a decrease of the maximal junction temperature of the SiC Schottky diode from TJ=260 °C to TJ=180 °C if the diffusion solder is used independent from the package type.

A Fully Electrically Isolated Package for High Temperature SiC Sensors

“…The experimental results of a novel fully electrically isolated package solution are reported in this paper. The geometry of this package was designed to fulfill the electrical isolation specifications required to connect the temperature probe to a standard measuring and acquisition data system from the cement industry [1]. The package capsule is shown in Fig.…”

“…In the normal operation of the packaged SiC temperature sensor, a hazardous voltage between the sensor terminals and the package casing might occur [1]. In order to determine the effect of such a parasitic voltage, several voltage bias levels (up to 100V) were applied between the package case and one of the sensor terminals, and the corresponding leakage current was measured.…”

“…Schottky barrier diodes (SBDs) are frequently used as temperature sensors in a wide variety of moderate-precision temperature measurement applications. Silicon SBDs can be used as temperature sensor at temperatures up to 130 o C. Silicon carbide (SiC) based sensors withstand significantly higher temperatures than silicon or silicon on insulator (SOI) ones due to the material's wide bandgap, leading to low intrinsic carrier concentration at elevated temperatures [1]. The fact that SiC is chemically inert in many environments, even at elevated temperatures, makes it suitable for electronics devices and sensors operating in harsh environments, such as cement fabrication chambers [2,3].…”

“…The fact that SiC is chemically inert in many environments, even at elevated temperatures, makes it suitable for electronics devices and sensors operating in harsh environments, such as cement fabrication chambers [2,3]. However, SiC electronic chips have reduced capability to work in hostile environments if they are not reliably packaged and connected [1].…”

Power diamond vertical Schottky barrier diode with 10 A forward current

“…In the other semiconductor materials like SiC, dopants are already fully ionized at room temperature and further temperature rise causes only mobility reduction. Thus, the efficiency of SiC diodes is limited by the thermal resistance of the crystal-case interface and the efficiency of the heat dissipation design [15]. The opposite situation takes place in diamond devices.…”