TRONIC'S Microsystems -, France
TRONIC'S Microsystems is producing 10,000 wafers per year at its MEMS (Micro Electro Mechanical Systems) site in Crolles, France. The company has built the new clean room in an existing facility. Since then, work has expanded the original production capacity by almost ten times at the end of 2004. Then, the equipment was converted from 100mm (4in) to 150mm (6in).
The company's existing 1,250m² building has 600m² of office space and a 650m² production area, of which 400m² are clean room facilities. Total investment was €6.5 million: €2 million for the clean rooms and €4.5 million for the equipment. TRONIC'S is now producing high performance inertial sensors at the plant.
TRONIC'S produces custom high-end MEMS components for demanding applications. The company is involved in the development and production of sensors, optical MEMS, RF MEMS and precision microstructures. TRONIC'S core technologies are based on thick silicon on insulator (SOI) surface and high aspect ratio micromachining technologies. For example, TRONIC'S has been producing capacitive accelerometers that have been used in pacemakers to regulate the electrical impulses depending on a patient's activity level. In November 2003, the French manufacturer also announced that it is manufacturing geophones for Sercel, a world leader in seismic exploration equipment for the petroleum industry.
The company offers a MEMSOI MPW (multi-project wafer) service, which reduces entry costs for customers into MEMS projects. Common designs fabricated with the service include high performance capacitive inertial sensors (accelerometers and gyrometers, for example) and electrostatic optical actuators.
In January 2005, Tronic’s opened a North American office for high-performance MEMS. The US has in recent years seen production across a broader number of applications, from industrial instrumentation to biomedical equipment. Gyrometers and bioMEMS applications are particularly expanding. MEMS developers are now focusing on more practical and simpler devices than before.
METAL SURFACE MICROMACHINING
TRONIC'S Microsystems is also developing metal surface micromachining processes for making tunable capacitor and integrated coil based RF MEMS devices with a leading telecom OEM. The company is involved in a three-year "Wide RF" European research project on 0.8GHz to 10GHz microsystem architectures. The project also involves EPFL (CH), HELIC (GR), INPG/LPCS (FR), Thales Airborne Systems (FR) and University of Cambridge (UK). The organizations are developing design and production technology for RF MEMS devices like RF switches, tunable capacitors and inductors.
The Wide RF project will also develop modeling and simulation tools and perform reliability studies. Part of TRONIC'S contribution will be wafer level packaging expertise, helping solve RF MEMS packaging issues like parasitic capacitances. Applications include aerospace, satellite electronics (smart antennas), cellular telephony and WLAN.
Some MEMS devices requiring very high sensitivity or very low noise (high Q factor resonators, for example) need to be vacuum packaged. Tronics' also offers a high Q vacuum packaged inertial sensor having a silicon die mounted in a leak free ceramic LCC housing, and vacuum sealed by eutectic bonding. The vacuum level, correlated with mechanical resonance coefficient, is better than 0.1mbar and can be lower than 1mTorr (0.0013 mbar) with a very high stability over time.
Wafer level packaging techniques bring two key advantages: the possibility of batch processing and protection of microstructures during dicing. TRONIC'S has produced wafer level Chip Size Packaged accelerometers since 1999, and more recently inertial sensors.
TRONIC'S develops optical MEMS, including wafer level packaged 1x40 micro-mirror arrays. The company has also been developing an optical wafer level package dedicated to optical micro-mirrors arrays. It has a glass cap treated with anti-reflecting coating, and uses a low temperature bonding process to protect the mirror coating. The mirror command electrodes can be accessed via wire bonding.
HIGH-END CUSTOM MEMS
TRONIC'S Microsystems develops and manufactures custom MEMS (Micro Electro Mechanical Systems) and microsystems for high end applications in low to medium unit volume.
The company is a spin-off from CEA Leti, and has a strategic partnership with the Laboratory. It has transferred production from the CEA Leti site to its new Crolles site, a task simplified by using compatible equipment for production, packaging and testing. There is a three-year MEMS R&D agreement between the two organisations, with a joint research team preparing TRONIC'S next generation technologies.