Munich, Germany – November 14, 2006 – Today at the electronica Trade Show, Infineon Technologies AG (FSE/NYSE: IFX) unveiled its new “miniature” silicon microphone for consumer and computer communications devices that is approximately one-half the size and operates on just one-third the power of conventional microphones. Based on silicon MEMS (micro-electrical-mechanical system) technology, the new microphone achieves the same acoustic and electrical properties as conventional microphones, but is more rugged and exhibits higher heat resistance. These properties offer designers of a wide range of products greater flexibility and new opportunities to integrate microphones.
The new silicon MEMS microphone that is much more heat-resistant and rugged than the typical microphones used today, which are based on electret condenser microphone (ECM) technology. The silicon MEMS microphone developed by Infineon can withstand temperatures of up to 260 C and is much more immune to vibrations and shocks. Due to the high temperature-resistance, it can be soldered without difficulty onto any standard PCB and is ideally suited to use on fully automated production lines common to mass market consumer products. A 1.5 to 3.3V power supply slashes the miniature microphone's power consumption to about one third (70 µA) that of ECM microphones.
The microphone consists of two
, the MEMS chip and an application-specific integrated circuit (ASIC), both of which share the same package on a surface-mounted device. The MEMS consists of a rigid, perforated back electrode and a flexible silicon membrane that serves as a capacitor, transforming acoustic pressure waves into capacitive variations. The ASIC detects these variations, converts them into electrical signals and passes them to the appropriate processing devices, such as a baseband processor or amplifier.
Silicon MEMS microphones can be used in anything from new mobile handset and headset models, to consumer electronics and notebook applications, medical systems, such as hearing aids, and even for such
as hands-free talking facilities.
“We can even envision using these microphones in
as acoustic sensors to monitor machinery for example,” says Peter Schiefer, head of the Discrete Semiconductors business unit at the Automotive, Industrial and Multimarket business group of Infineon Technologies.
The Infineon silicon MEMS microphones is unique because the company is the only provider that combines MEMS and ASIC expertise in one package and offers the associated production skills, all from a single source. The technology used to manufacture the MEMS microphones was developed at Infineon in Villach, Austria.
Market researcher firm Wicht Technology Consulting (WTC) estimates that the market for silicon microphones will grow from US $56 million in 2005 to US $680 million in 2010. “We believe that silicon microphones will quickly become an established product in the market, and we are making sure we have appropriate production capacity,” Schiefer stated in response to the market research. “Our goal is to become the leading provider of silicon microphones.”
The new silicon MEMS microphone broadens the Infineon existing portfolio of mechanical and radio-frequency MEMS products, which include accelerometers, gyroscopes and pressure sensors and bulk acoustic wave (BAW) filters.
Technical properties of the new MEMS microphone
The silicon MEMS microphone from Infineon features excellent acoustic properties such as high signal-to-noise ratio (59dB(A)) and high sensitivity (10mV/Pa). Thanks to these properties, it is a substitute for electret microphones. The silicon MEMS microphone also remains very stable at different temperatures.
The compact, flat package (4.72 mm x 3.76 mm x 1.5 mm) opens a far wider choice of product design options than for larger microphones. Also, several identical individual microphones can easily be configured to form the arrays needed for directional microphones, as the conformance of silicon microphones can be ensured and variations over time remain low. A further outstanding feature is the new microphone's low power consumption, which averages 70 µA. Operating voltages range from 1.5 to 3.3V.