Manufacturing and packaging of sensors for their integration in a verticalMCM microsystem for biomedical applications

The goal of this work is to demonstrate the feasibility of integrating frag ile micromachined chips into a complex three-dimensional (3-D) multichip mo dule (MCM) microsystem for a biomedical application. The system is based on the vertical integration of the different parts: micropumps and valves, a multisensor chip for on-line control of the system and a signal-processing chip. In this paper, packaging of the microsystem is studied in order to mi nimize the induced stress that can affect the integrity of the different mi cromachined parts of the system. Standard commercially available components and materials were used so as to minimize costs for the case of high volum e packaging. For testing the approach, a multisensor chip which includes th in silicon membrane-based devices has been used as the main test structure to compare different packaging materials. In addition, for the fabrication of such a sensor chip in an efficient mode, technological modules needed to fabricate sensors on complementary metal-oxide-semiconductor (CMOS) wafers are discussed. The definition of standardized "add-on" sensor modules to t he CMOS process of a foundry is intended to limit the development cost of s mart sensors.