We’ve already heard that microelectromechanical systems (MEMS) ICs have been on the verge of penetrating mass-market applications. However, aside from traditional automotive and medical electronics applications where MEMS pressure sensing constitutes the bulk of their use, they haven’t yet made large gains in mass-market applications like mobile phones, PCs, and many other consumer electronic items. But that seems to be changing quickly, judging from presentations at the MEMS Executive Congress meeting held from Nov. 5-7 in Scottsdale, Ariz. Driving all this is a new generation of MEMS microphones, timing devices, tri-axis accelerometers, RF MEMS ICs, as well as improvements in manufacturing using CMOS processing.
According to a keynote presentation given by David Smith, Vice President for consulting, alliances and education at Technology Futures Inc., and an internationally known futurist, the worldwide market for MEMS ICs will nearly double to close to $10 billion by 2010, much of it in devices for mass-market applications (see Fig. 1). That same forecast is shared by French market research firm Yolé Developpement.
These new lucrative markets are presenting MEMS IC manufacturers with challenges to devise the proper testing, packaging and manufacturing strategies to satisfy the low-cost demands of mass-market applications. MEMS IC manufacturers are confident, however, that they can meet these challenges, many of whom have had at least two decades of experience in manufacturing MEMS products.
CONSUMER ELECTRONICS IS GUNG HO
MEMS ICs are now finding use in a variety of consumer electronics products like digital cameras, camcorders, video games, PCs, iPods, PDAs, GPS devices, sports and fitness machines, home healthcare products, etc. Many estimates predict that MEMS ICs could grow from the present 5-6% in the consumer electronics sector alone to 20-25% in the next few years.
Just look at Nintendo’s ingenious Wii (pronounced “whee”) video game system to appreciate how far MEMS ICs have come in the consumer electronics field. The console’s wireless controller, nicknamed the Wiimote, allows the system to be totally sensitive to any motion in every axis thanks to the use of MEMS accelerometers. The system can mimic a baseball bat, ping-pong paddle, tennis racket, conductor’s baton, fishing rod or a sword (see With Wii Remote, Gaming Is Child's Play).
German market forecaster Wicht Technologie Consulting predicts that the market for MEMS inertial sensors (accelerometers and gyroscopes) for consumer applications is set to grow from $835 million in 2004 to over $1360 million in 2009, a compound annual growth rate (CAGR) of 10%.
There are many MEMS IC applications beyond the usual video games and other hot items in consumer electronics. These include hard-disk drives (HDDs) and high-definition TVs (HDTVs) that use MEMS micromirrors and digital light-processing (DLP) technology. VTI Technologies sells a 3D MEMS IC that’s used in sports and health wellness applications like sports watches and bicycle computers.The Dixx Blu Golf Training device from Infinics and the SwingHat.smart Golf technology from the Swinghat Co. use MEMS accelerometers to help golfers improve their swings.
MOBILE PHONES
Mobile phones loom as a huge market for MEMS accelerometers, microphones, and RF MEMS. Yolé Developpement forecasts an $845 market by 2009 ( see Fig. 2). Motion sensing for blur-free camera phones is a target feature MEMS IC makers are aiming for. This feature is beyond the capability of present MEMS accelerometers but can be handled with miniature integrated inertial measurement units (IMUs), which are under development. IMUs measure all axes of motion and integrate three axes of angular rotation and three axes of linear motion. Invensense has produced a dual-axis MEMS gyroscope for digital and still video cameras for image stabilization, which it believes can be a cost-effective solution for mobile phones.
There’s some skepticism on how successful MEMS can be in penetrating mobile phones on a large scale save for some high-end phones where additional functions can be had for an acceptable increase in the phone’s price. Beneditto Vignas director of the MEMS business unit for ST Microelectronics cautions that “it takes a very different approach to redesign a MEMS IC to meet rapidly changing consumer electronics demands than redesigning a CMOS IC. Life cycle spans for consumer electronics are very different than those say for automotive electronics, forcing MEMS IC providers to very carefully weigh their risks in doing business in the consumer market.”
The flip side of that statement is the fact that many steps in the manufacturing process of MEMS ICs are being made on standard CMOS processes, often at semiconductor foundries, with certain steps like the “lift-off” procedure being performed at the MEMS IC manufacturing facility.
Still, MEMS IC manufacturers are aggressively pursuing the mobile phone market as the next MEMS “killer” application. They see convenience features like handset accelerometers that detect the user’s action of picking up the phone and raising it to the ear, automatically shutting off the display to save power. Another useful function would be an accelerometer that lets users scroll down Web sites by tilting the phone. In Japan, Fujitsu is selling mobile phones with three-axis MEMS accelerometers that function as pedometers. And Nokia has demonstrated a MEMS-based mobile phone with wave messaging that allows the user to paint messages in the air, as well as play games by tilting and moving the phone.
Mobile phones have always been a lucrative, yet difficult to hit, market for RF MEMS ICs. Jeff Hilbert, president and CEO of WiSpry believes for the industry to be successful here RF MEMS must be able to offer an added benefit to the mobile phone that no other technology can offer, and only for a small increase in price. Nevertheless, RF MEMS IC manufacturers are confident that they can bring the price of RF MEMS ICs down with improved manufacturing methods and thus open up large mobile phone applications. Rick Thompson, manager of advanced technologies for BAE Systems mentioned impedance matching as a viable application, where the MEMS IC, acting as a switch, would cut in to match a low or lost signal to the phone in low-signal areas until a stronger signal is acquired, then shut down.
One major (though not well-publicized) application for RF MEMS in terms of large unit volume sales is as switches for automatic test equipment (ATE) test heads. Companies like TeraVicta Technologies Inc. work with the major ATE system manufacturers to provide them with millions of RF MEMS switches.
TIMING AND MICROPHONE DEVICES EMERGING
The time has come for the MEMS oscillator. A flurry of announcements late last year, first by SiTime, followed by Discera, has revved up interest in the use of CMOS MEMS oscillators as timing circuits to replace the venerable quartz crystal oscillator. Both expect to ship volume quantities by next year. A third company, Silicon Clocks, is mum about its MEMS oscillator design but is expected to join the market soon. All three companies are typical of the fabless design houses that create the IC design, then have an outside foundry house produce it using a CMOS process that handles most of the chip’s processing steps. Wicht Technologie Consulting predicts that by 2012, the MEMS oscillator market will reach $200 million, up from a very small market this year (see Fig. 3).
SiTime is using a Bosch licensed process to produce its product. It is working with the Silicon Valley Technology Center (SVTC), a business unit of Cypress Semiconductor, to achieve a “lab to fab” capability as promoted by SVTC, for its product’s production. Recently, Discera signed a very broad agreement with Vectron, a major quartz crystal manufacturer, which involves all aspects of the design, development and manufacture of Discera’s MEMS timing ICs.
Another MEMS entry into mass-market applications is the microphone, spearheaded by Akustica’s announcement early this year of the first integrated CMOS MEMS IC. Knowles Acoustics also produces SiSonic MEMS microphones. However, unlike Akustica’s single-chip approach, they use a silicon microphone together with an ASIC. The newest entry in this market is Infineon Technologies with a miniature MEMS microphone it unveiled at Electronica (see Fig. 4). All of these microphones are aiming to replace the decades-old electret condenser microphone (ECM).
The key element in all of these aforementioned mass-market applications will be to make MEMS sensors more attractive. This requires bringing down costs and achieving higher levels of integration, and functionality, which in turn means the use of standardized packaging, testing and manufacturing approaches. In the meantime, MEMS IC manufacturers continue to refine and advance their product offerings in their traditional markets like the automotive sector, focusing on smarter air-bag sensors and tire-pressure monitoring systems (TPMSs).