Fabrication and Assembly of a Digital Transducer-to-Bus Interface Module Having a Directly Attached MEMS Device

摘要

Boeing has developed a smart sensor system suitable for flight loads testing, which can accommodate large arrays of sensors in a bus configuration. In this paper, we report the development of a digital transducer-to-bus-interface module (TBIM) packaged as a multi-chip module (MCM). The most significant aspect of this module is the increased functionality at the sensor location. With local digital conversion, robust communication to the host computer is possible through a common bus eliminating the need for discrete wires. We also describe the fabrication and assembly processes used for this module, which contains a bare MEMS device, two ASICs (one analog and one digital), two memory chips and a number of discrete components. The MCM substrate was fabricated on silicon using copper as conductor and polyimide as dielectric. The MEMS device was bonded using direct-chip-attachment process (flip chip) while other components were attached using conventional microelectronic interconnection and surface mount techniques.