SensoNor: MultiMEMS process

SensoNor will offer design training in a bulk micromachining process platform (the MultiMEMS process - Figure 1). Highlight of this process includes bulk micromachining of two thicknesses in the same chip, piezoresistive detection and thermal excitation. The patented triple-stack glass-silicon-glass wafer level packaging method that is an integral part of this process is proven to give products with very good media compatibility and very good long-term stability. The MEMS chips made in this process are robust and easy to use in the next integration level and make possible development of highly reliable industrial products. The process has already proved to be very flexible with more than 50 designs already made in MPW and custom designs so far in the NORMIC and MultiMEMS Europractice projects, covering different types of microsystems including absolute and differential pressure sensors, flow sensors and other microfluidic devices, acceleration sensors, force sensors and gas sensors. The MultiMEMS MPW service offers chip sizes of 3x3 mm2, 3x6 mm2, 6x3 mm2 and 6x6 mm2. Together with the research partners SINTEF ICT and Vestfold University College, SensoNor covers a complete development track from idea, through feasibility, design and processing of prototypes in packaged form, to volume manufacturing of MEMS.

Figure 2 : Cross-section of the MultiMEMS process (not to scale) showing the triple-stack glass-silicon-glass structure with a mass-spring system with piezoresistors in sealed cavity to the left and an etched diaphragm with buried piezoresistors, vacuum reference volume and inlet port to the right. The patented method of using buried diffused conductors for crossing of the sealing areas is also shown. 

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Figure 3 : 3D views of (a) typical completed triple-stack glass-silicon-glass structure with two sensors on the same chip and (b) the silicon part of the same chip with the micromachined structures.   

Figure 4 : SensoNor’s System-In-Package (SIP) concept by using cavity packages for surface mount. 

For more information please consult: www.multimems.com