Electrical and Mechanical Characterization of Low Temperature Co-fired Ceramics for High Temperature Sensor Applications C. Bienert 1 , A. Roosen 1 , M. Grosser 2 , M. Ziegler 2 , U. Schmid 3 1 University of Erlangen-Nuremberg, Department of Materials Science, Chair of Glass and Ceramics, Martensstraße 5, 91058 Erlangen, Germany 2 Saarland University, Faculty of Natural Sciences and Technology II, Chair of Micromechanics, Microfluidics/Microactuators, 66123 Saarbruecken, Germany 3 Department for Microsystems Technology, Institute of Sensor and Actuator Systems, Vienna University of Technology, Floragasse7, A-1040 Vienna, Austria ABSTRACT To make use of metals with improved conductivity like Ag, AgPd, Au or Cu for metallization pastes in ceramic multilayer technology, Low-Temperature Co-fired Ceramics (LTCC) are densified at temperatures below 900°C. The densification mechanism can be attributed to viscous sintering in combination with the crystallization of the glass matrix. Lifetime prediction and extension of the application range to elevated temperatures strongly depend on the transition range of the remaining amorphous phase as well as on the final crystallization products. Due to the fact that multilayer ceramics based on LTCCs are gaining increasing interest in the manufacturing of highly integrated devices for microelectronic and sensor applications, there is the need to establish a better understanding of their mechanical and electrical behaviour in the elevated temperature regime. In this study, four commercial LTCC substrate materials in addition to a test product in the sintered state, namely DP 951, DP 943, both from DuPont, CT 800 and AHT-01, both from Heraeus, and GC from CeramTec were investigated in respect to the temperature dependence of their mechanical and electrical properties up to temperatures of 950 °C. Mechanical characterization included three-point bending tests on single layer substrates. Furthermore, the surface resistivity as a function of temperature up to 500°C was determined under vacuum for DP 951. Next, these results were correlated to the composition of the glasses, determined by inductively coupled plasma (ICP) analysis, as well as the crystallization products apparent in the composites, which were determined by XRD of the sintered substrates and in-situ HT-XRD for DP 951. Results gained from these investigations of the commercial LTCC products were compared to measurements carried out on glass-ceramic composites developed in-house exhibiting improved electrical behaviour and good temperature stability. Keywords: LTCC, high temperature behaviour, mechanical behaviour, electrical performance, glass softening INTRODUCTION First introduced in microelectronics in the early 90s, the application fields for low temperature co-fired ceramics (LTCC) composite materials have increased significantly. Due to the fast technological improvements in microelectronics and micromechanical components, increasing demands arise for highly integrated ceramic multilayer devices with compact electrical assemblies, smaller power loss, as well as high signal density and signal velocity [1, 2]. Filled glass-ceramic composites combine the possibilities of thick film technology and high temperature co-fired ceramics technology with the advantage of low sintering temperatures of < 900°C [3, 4]. Improving the performance of multilayer devices which are used in a broad field of applications in electronic packaging and microsystems [5], the low sintering temperature permits the application of metal pastes with high electrical conductivity like Ag, AgPd, and Au for co-firing [4]. The Smart Sensors, Actuators, and MEMS IV, edited by Ulrich Schmid, Carles Cané, Herbert Shea Proc. of SPIE Vol. 7362, 73620V · © 2009 SPIE · CCC code: 0277-786X/09/$18 · doi: 10.1117/12.822665 Proc. of SPIE Vol. 7362 73620V-1