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July 18, 2003 – As tiny microphones built with small tech are getting ready to leap into mobile phones, hearing aids, personal digital assistants and MP3 players, there’s already some competition brewing. Akustica Inc. and Knowles Acoustics Inc., with Denmark’s SonionMEMS as a dark horse, are vying for market leadership in MEMS-made mikes.
“MEMS microphones are here now,” said Akustica Chief Executive James Rock. “They are being designed into roadmaps for 2004 products. And companies are becoming more aware of their benefits.”
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Etched in silicon with techniques based on computer chip-making processes, MEMS microphones’ initial value may not be price, but reduced manufacturing costs of electronic devices.
Bell Labs scientists invented the electret condenser microphone (ECM) in 1962. Today more than a billion ECMs are sold annually by giants like Panasonic for as little as 50 cents apiece.
But because ECMs can be damaged by high heat, they must be soldered in place by hand. Such a manual step can be a costly bottleneck in the automated assembly of high-volume, low-margin electronic products such as the 480 million mobile phones to be made in 2003.
As Knowles Acoustics General Manager Jeffrey Niew explains, a silicon microphone can withstand the 260-degrees Celsius soldering temperatures in modern, automated “pick-and-place” assembly processes. Niew said the cost of placing a silicon microphone in a device could be as much as 10 times less than installing a condenser mike.
Based in Itasca, Ill., Knowles launched its SiSonic silicon microphone in early 2003 and already is supplying it to Swedish mobile-phone maker Neonode. SiSonic product manager Mike Adell said that the company is supplying MEMS mikes “in really high
volume” to an even larger mobile phone maker he declined to identify.
Knowles, previously known as Emkay Innovative Products, is a division of $200 million hearing aid component maker Knowles Electronics LLC. The company plans to sell its 6mm x 3mm x 1.4mm mike-and-amplifier packages for use in consumer electronics devices such as video cameras.
Niew expects that by 2004, silicon microphones will account for 30 percent to 40 percent of Knowles Acoustics’ business. But he acknowledged that getting companies to change entrenched manufacturing processes, even for a better sonic mousetrap, will be challenging.
In April, Akustica, a well-funded Pittsburgh startup, introduced an acoustic chip that integrates a membrane of 64 tiny sound-sensing diaphragms of silicon with sound-processing electronics that can help cancel out background noise. While it is also greatly interested in the large mobile phone market, it hopes to showcase its integrated electronics on a next generation hearing aid in collaboration with GN ReSound in Denmark.
Rock said that the 3mm x 3.65mm x .55mm device can be manufactured in the existing CMOS chip foundries, including those such as giant Taiwan Semiconductor Manufacturing that already supply phone handset makers.
Knowles said that its MEMS mikes will be fabricated in mainline chip-making plants, and that it has a production agreement pending with “a global semiconductor and software” company.
While Akustica’s Rock thinks there’s room for several players to succeed, he contends that his company’s system-on-a-chip approach is fundamentally superior to Knowles’ system-in-a-package approach, in which two or more components are soldered together.
He also cites similar advantages over the three-piece solution from SonionMEMS, a new subsidiary of Denmark-based Sonion, which entails wafer-bonding three components together.
Rock argues that microphones like Akustica’s built-in silicon with directly integrated electronics can reduce costs even more by eliminating the need for subcomponents such as amplifiers and analog-to-digital converters. Thus a $3 or $4 acoustics system (Akustica hasn’t revealed actual pricing) could potentially replace $5 or more in parts.
Knowles’ Niew concedes that Akustica’s integrated approach makes sense, but believes the approach will be too costly and complex in the near term.
“Companies won’t pay a premium for a MEMS microphone right now,” said Niew.
Rock’s Akustica counters that his company’s broad intellectual property on the integrated acoustic chip means competitors have no choice but to champion their own approach.
Leo O’Connor, research director with Frost & Sullivan’s Technical Insights, sees MEMS microphones as a promising technology converging with a rapidly growing market.
“Whether microphones follow sensors as the next successful MEMS application remains to be seen,” he said.
Much will depend on how quickly cell phone and PDA device companies are willing to adopt them.