FREQUENCE 2009

Quartz is the best suited material to produce ultra stable (5 to 10 MHz) or high spectral purity (around 100 MHz) oscillators, both for military and space markets. The most optimised high performance, severe conditions quartz resonator version is the BVA (‘Boitier à Vieillissement Amélioré’: Improved ageing package), which was developed 30 years ago by R. Besson. BVA technology did not perform evolution since then, as, at the same time, electronic continuously moved toward increasing integration and miniaturization. In order to remain a mandatory material, quartz has to follow the same way. This project is focusing on this objective. Conditions are fulfilled now: On one hand, multi applications simulation tools are now ready to fully implement quartz modelization. On the other hand, innovative technological processes, such as micro-machining, multi-layer assembly or wafer-bonding, can be successfully applied to quartz, in order to miniaturize packaged resonators while optimising their performances. In order to satisfy the expected technological breakthrough, it is forecasted in this project to modelize and develop all mandatory processes, which will allow reviewing the above mentioned BVA technology. A significant gain in terms of size and cost (at least an order of magnitude) due to collective processes is expected. This should be achieved without trade-off with ultimate component performances, in terms of ageing, radiations or g- sensitivity and phase noise. In order to address this challenge, TEMEX is associated with FEMTO-ST institute and with GEMMA. This cooperative R&D effort should lead to the mergence of a new quartz resonator generation. As project leader, TEMEX will set up the resonator operational requirements while taking into account a system approach. TEMEX will manage as well demonstrator’s fabrication, including all associated qualification processes. FEMTO-ST will develop the simulation models, together with all necessary new technologies. This will be achieved in close cooperation with TEMEX, in the frame of Common Laboratory developed between the two companies (LPMX). GEMMA, which is a specialist of quartz crystallogenesis, will develop high size high quality materials. High size wafers are now indeed becoming a standard for collective processes (100 mm diameter).