Graz-based start-up USound, in partnership with several Fraunhofer Institutes (IDMT, ISIT, IIS and IZM) and utilizing PCB technology together with system integration expertise from AT&S, has developed what is not only the world’s smallest speaker, but also the first based on micro-electro-mechanical systems (MEMS). The product is protected with numerous patents. MEMS are silicon chips or substrates with very small feature sizes, that have mechanical and electrical functions at the same time. They make it possible to implement extremely compact, reliable and energy-efficient solutions. With dimensions of just 5 mm x 7 mm x 2 mm, the micro-speaker has a frequency range of 2-15 kHz.
AT&S is a technology partner of USound. Development of the MEMS micro-speaker would not have been possible without innovations in materials, silicon integration and packaging. Thanks to state-of-the-art packaging solutions, the MEMS loudspeaker itself, its drive circuits (application-specific integrated circuits, ASIC) and passive elements can be integrated into a tiny component with an extremely small form factor.
To manufacture ultra-small components of this kind, innovative system integration is essential in addition to state-of-the-art printed circuit board (PCB) technology. Thus AT&S have developed not only optimised PCB technology, but also special process engineering solutions for component and semiconductor packaging – from embedding passive components to complete System-in-Boards (SiB) and System-in-Packages (SiP). A wide range of innovative products based on AT&S technologies are manufactured in large volumes, from miniaturised computer boards to medical sensor products and MEMS microphones – and now MEMS speakers too.
While MEMS components are widely used as acceleration and tilt sensors, and as microphones, in smartphones, wearables and vehicles, MEMS-based speakers did not exist until now. By eliminating the coil and magnet found in conventional solutions, MEMS speakers achieve extremely small dimensions along with low power consumption and very good sound quality.
USound will transfer the presented technology into mass production. The new generation of speakers based on semiconductor technology is set to come to market in 2018. They will require only half as much space and 80 percent less power than their predecessors. USound is also aiming to create better sound quality with its MEMS speakers than with conventional speakers.