A Fully Electrically Isolated Package for High Temperature SiC Sensors

Abstract

A fully electrically isolated package for a SiC temperature sensor, able to work at high temperature, is presented in this paper. The adopted packaging solution was tested under thermal stress by varying the temperature between 300C and 400C (for 500 cycles) and between 50C and 400C (for other 500 cycles). The thermal stress had negligible effect on the capsules leakage currents (measured from the sensor terminals to the package metal casing) and did not degrade the glass which ensures the sealing of the capsule. The measurements and microphysical investigations showed a stable operation of the package up to temperatures of 400C.

Two Packaging Solutions for High Temperature SiC Diode Sensors

“…A novel layout with a circular, 200µm diameter, Schottky contact was designed. A large area pad was added in order to enable the electrical connection between the SBD structure and the anode package terminals [2][3][4]. An oxide ramp field plate termination was employed in order to ensure the uniform current distribution at the Schottky contact.…”

“…Both methods lead to more flexible architectures, in which the sensor has increased degrees of freedom within the capsule. The geometry of the packages was designed to fulfill the electrical isolation specifications required to connect the sensor to a standard measuring and data acquisition system used in the cement industry [2][3]. The packaging capsules are shown in Figs.…”

“…Emission control for both real time monitoring and feedback control of exhaust products in the automotive or cement industries require sensors that can operate in chemically reactive high temperature environments. The SiC Schottky barrier diodes (SBDs) are frequently used with high performances as temperature sensors in a wide variety of moderate-precision temperature measurement applications [1][2][3][4]. SiC electronic chips have reduced capability to work in hostile environments if they are not reliably packaged and connected [1].…”

“…In a previous paper, we have described a temperature probe sensor, designed for use in the cement industry, based on SiC SBDs. In this paper we compare the behavior of two identical SiC SBD sensors: i) one mounted in a fully electrically isolated package, using a mechanic piston [2] ii) and the other using a standard Au wire bonding package solution [3]. Electrical and optical characterizations of temperature sensors mounted in these packaging technologies are presented.…”

Two parameter extraction solutions for high temperature SiC Schottky diodes — Converging to reality

“…Due to the properties of silicon carbide, mainly its wide bandgap and chemical stability, Schottky diodes based on this material can be used with high performances as sensors in such environments [1,2,3]. Packaging these devices in a reliable way is another important aspect to take into consideration [1].…”