Title:CMOS Integrated Stress Sensor Systems for Mechanical Sensing and Packaging Monitoring

Speaker:Prof. Oliver Paul（University of Freiburg, Germany）

Abstract: After a brief introduction of the broader activities of the presenter’s group, the talk will address novel developments of microsensors and microsystems based on complementary metal oxide semiconductor (CMOS) technology for measuring mechanical stress and their applications. The stress acting on the sensors may originate from effects internal or external to the package of the sensor chip. Therefore, in a first application area, the systems make it possible to measure external mechanical constraints such as force and torque. Sensors and systems for this application category include tactile sensors, smart brackets, and a solid-state joystick with four degrees of freedom, among others. Secondly, the sensors have proven useful for the measurement of thermomechanical forces acting on encapsulated microchips and thus for studying the reliability of advanced microelectronic packaging technologies. The implemented systems rely on sensors for the measurement of in-plane stresses. For packaging testing, novel structures sensitive to out-of-plane stress components had to be developed and will be presented in the talk.

Biography:Oliver Paul received the Diploma degree in physics and the D.Sc. degree from the Swiss Federal Institute of Technology (ETH), Zurich, Switzerland, in 1986 and 1990, respectively. After postdoctoral work at the Fraunhofer Institute for Solar Energy Systems, where he contributed to the technology and modeling of high-efficiency silicon solar cells, he joined the Physical Electronics Laboratory, ETH Zurich, in 1992, as a Lecturer and Group Leader. Since 1998, he has been a Full Professor at the University of Freiburg, Germany, where he heads the Laboratory for Microsystem Materials at the Department of Microsystems Engineering (IMTEK). He is a coauthor of more than 270 technical publications, three patents and nine patents pending, and four books. His research has targeted the development, characterization, and application of MEMS materials and of MEMS fabrication processes compatible with silicon technologies, in particular CMOS technologies. These activities are motivated by academic and industrial applications of microtransducers and microsystems for the life sciences, in particular neurotechnology, and for the measurement of physical quantities including mechanical stress, magnetic field and temperature. Dr. Paul is a member of the IEEE, of the Editorial Boards of Sensors and Actuators A: Physical and Journal of Micromechanics and Microengineering, and of the Editorial Advisory Board of the IEEJ Transactions on Electrical and Electronic Engineering. He is a cofounder of the MEMS company Sensirion AG, cochaired the IEEE MEMS 2004 Conference in Maastricht, The Netherlands, January 25–29, 2004, and headed the Ph.D. program in Embedded Microsystems at the University of Freiburg from 2005 to 2009. From 2006 to 2008, he has served as the Director of IMTEK.