Articles | Volume 5, issue 1
Review paper
17 Mar 2016
Review paper |  | 17 Mar 2016

Investigation of low-temperature cofired ceramics packages for high-temperature SAW sensors

Jochen Bardong, Alfred Binder, Sasa Toskov, Goran Miskovic, and Goran Radosavljevic

Abstract. Surface acoustic wave (SAW) temperature sensor devices have been developed for operating temperatures up to and above 1000 °C. A challenging task to make these devices available on the market is to develop an appropriate housing concept. A concept based on low-temperature cofired ceramics (LTCC) has been investigated and tested under elevated temperatures up to 600 °C. The devices showed promising results up to 450 °C. Thorough analysis of the possible failure mechanisms was done to increase the maximum temperature above this limit in further production cycles.

Short summary
In this work, a ceramic housing was designed using the versatile low-temperature cofired ceramics (LTCC) to test this technology at temperatures above 400°C. Inside the housing, a prototype sensor chip was mounted to monitor the signal quality during an applied heat treatment up to 600 °C. All devices failed at around 450–500 °C due to material migration from the glass seal of the housing to the sensing structures of the mounted chip. Elemental analysis identified bismuth as a contaminant.