Robust Class-I BME Ceramic Capacitors for High Temperature Applications

Abstract

In capacitors for applications at temperatures of 150°C or above, such as automotive under-the-hood electronics and power electronics, a robust dielectric material is necessary. In traditional X8R ceramic capacitors (EIA specification, ΔC/C within ±15% between −55°C and +150°C compared that at 25°C), the dielectric material is designed for applications up to 150°C. However, at temperatures above 150°C, the X8R capacitors typically suffer from degradation of reliability performance and severe reduction in capacitance, especially under DC bias conditions. Recently, a Class-I C0G dielectric has been developed using Nickel electrodes for high temperature application up to 200°C. Due to its linear dielectric nature, this material exhibits highly stable capacitance as a function of temperature and voltage. Multi-layer ceramic capacitors (MLCC) made from this material can be qualified as X9G with robust reliability. This paper will report electrical properties and reliability test data on these Class-I C0G ceramic capacitors at temperatures ≥150°C. In addition, test data from D-E curves and energy density measurements will be reported along with a discussion of possible mechanisms behind the robust reliability of this material.