Here is the abstract you requested from the CICMT_2007 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|New Sacrificial Layer Based Screen-Printing Process for Free-Standing Thick-Films Applied to MEMS|
|Keywords: Free-standing thick films, Screen printed sacrificial layer, Hybrid MEMS|
|Standard screen-printing technology, mainly used in microelectronics for interconnexions and packaging purposes, has also been extended to the development of specific passive components (varistors, heating elements, etc) and sensors. A new process derived from this technology and based on thick sacrificial layers allowed us the fabrication of films partially released from the substrate. These free-standing thick films may be therefore actuated and used for hybrid MEMS applications. The process has been initially developed in our laboratory for the fabrication of an electrothermal actuator. This microsystem, screen-printed on a standard 96% alumina, consists of two linked copper beams of different widths partially suspended above the substrate to which they are anchored. Energy-dispersive X-ray analyses have demonstrated the harmlessness of the process with regard to the metallic layer. Whilst increasing dc voltage between both anchors, the deflection is optically measured using a calibrated CCD camera. The thermal microactuator has also been operated with an ac voltage, up to a frequency of 10Hz. Other developments in our laboratory of the thick sacrificial layer process include the fabrication of heating resistors and microchannels. Compared to screen printed resistors directly in contact with the alumina substrate, free standing resistors allow to reach higher temperatures with lower power consumption and with lower risk to explode the substrate. Microchannels of 500µm width and 50µm height have been fabricated with either glass or metal. Moreover, the process has been shown to facilitate the implementation of microassemblies such as piezoelectric transformers. These preliminary results demonstrate the efficiency of this simple, collective and low cost process. It is clear that this original method opens new routes of investigation for MEMS, complementary to silicon, LTCC, Ink jet and PCB ones, especially in the field of microactuators, microsensors, microfluidics, microrobotics...|
Université de Bordeaux