New applications along with manufacturing capabilities and technological readiness are driving the takeoff of micro-machined ultrasonic transducers.
MICRO-MACHINED ULTRASONIC TRANSDUCERS ARE COMING TO MARKET: WHY NOW?
For decades, micro-machined ultrasonic transducers, either in the form of PMUT (Piezoelectric micromachined ultrasonic transducers) or CMUT (capacitive micro-machined ultrasonic transducers), have been knocking at the door of mass-markets. At last, mass-market is about to happen: Why now?
There are four concurrent factors explaining this timing. First, applications are pushing for these technologies. Medical ultrasonic imaging will democratize into general practitioners and even homes, thanks to cheaper and smaller probes. In consumer applications, ultrasonic fingerprintsensing allows for under-the-display operation, resulting in all-screen smartphones just 10 years after the iPhone removed the keyboard.
Secondly, the technology is ready. PMUT, which requires a thin, controlled piezoelectric film, has benefited from this technology’s increased usage for inkjet printhead. Meanwhile, CMUT also requires a delicate manufacturing process with large and thin membranes, in which mechanical stress usually remains.
Thirdly, several industry players have consistently invested in these technologies, thus readying the supply chain: Hitachi and Philips for CMUT, Dimatix and STMicroelectronics for PMUT, and GlobalFoundries and Silex for both.
Last but not least, assembly is an important part of manufacturing, especially if mass-market is targeted. Companies like Tong Hsing Electronic, Philips, and SilTerra have readied the supply chain.
This alignment of favorable factors, similar to an arrangement of fortuitous stars, has set the stage for ultrasonic sensing’s arrival in several applications and markets.
ULTRASONIC SENSING MODULES: A $2B MARKET IN 2017, POISED TO REACH AROUND $6B IN 2023
Thanks to new applications, the ultrasound modules market will boom in the next five years, at a CAGR2017-2023 of 18%! In 2017 the biggest market was park assist, followed by automation. But the impressive growth of the ultrasound modules market is coming from new applications in the fingerprint and medical markets. Fingerprint sensing will achieve the biggest growth, and with the integration of PMUT is poised to see the largest changes in terms of technology. From a small market in 2017, fingerprint sensing will reach $2B in five years thanks to its integration into smartphones.
The medical ultrasound market will also see many changes with the arrival of new products like the $2,000 Butterfly IQ ultrasound probe. This handheld, low-cost device will reshape medical ultrasound usage, with new customers such as primary care, emergency physicians, and nurses being able to use imaging as an everyday tool. Ultrasound might be the new stethoscope!
From a technology perspective, we see that the ultrasound modules market is today almost exclusively comprised of bulk piezoelectric transducers. This is the conventional method for ultrasound sensing and will remain the gold standard for applications like park assist and automation. CMUT, which was developed 30 years ago, is traditionally used in medical applications and, has only recently found its killer application: handheld ultrasound. Regarding PMUT, it will mainly be used in high-volume applications thanks to its high level of integration. Miniaturization, low cost, and integration are major drivers for ultrasonic transducers, which explains the popularity of new technologies coming from the semiconductor industry.
In this report, Yole Développement’s analysts explain how the ultrasonic transducer ecosystem may evolve, and how Micro-machined ultrasound transducer (MUT) technologies will rapidly penetrate the ultrasound market.
MAJOR MUT CHALLENGES SOLVED - AN INDUSTRY READY FOR PRODUCTION
MUT technologies have created a high level of excitement after a long, quiet period that lasted for 10 years after Hitachi introduced the first ultrasound technology probe. Not everyone was quiet, though: R&D teams still worked intensively to develop new ultrasonic transducers and overcome the challenges linked to MUT.
More than performance, MEMS devices require a huge investment in development and production tools. MEMS foundries are now ready to offer services for ultrasound devices. At the front-end level, the thin-film piezoelectric layer deposition process made huge progress and found the right uniformity and homogeneity. Work done on scandium-doped AlN by Dalsa (Teledyne Dalsa) and niobium-doped PZT (Fujifilm) has dramatically increased PMUT device performance.
CMUT’s main challenges were two-fold: the short lifetime of CMUT structures because of high electrical fields, and settling on the membrane material. Notably, Philips Innovation Services and Micralyne spent more than 15 years developing such capabilities.
MUT devices also impose strong assembly challenges. Due to its structure and the presence of electrodes on both sides, CMUT assembly is more complex than PMUT. For these reasons, PMUT is a better candidate for a high level of integration and miniaturization.
So, why now? And what happens 10 years? CMUT and PMUT usage are highly segmented by applications with a smooth difference in operational frequencies and operational medium: air or fluids. PMUT has a broader frequency range and can work in air and fluids better than CMUT. What does the future hold for both? Will their parallel development in their specific fields result in a winning technology that enables higher volumes and a wider applications range?
This report describes ultrasonic technologies’ current challenges, and offers a roadmap for the next decade.
OBJECTIVES OF THE REPORT
- Provide forecast metrics for each ultrasound sensing modules:
• Ultrasound market revenue and volume shipment forecasts at the system level for various industries
(consumer, medical, industrial and automotive)
• Ultrasound modules’ average selling price forecast, revenue forecast and volume shipments forecast
• Technology penetration rates: CMUT and PMUT technologies vs. bulk piezo
- Deliver an in-depth understanding of the ecosystem and players
• Who are the players from the various areas: foundry, transducer, packaging, system level integrator, etc.
• Who are the key suppliers and which technologies do they provide
- Share key technical insights and analysis on future technology trends and challenges
• The industry’s state-of-the-art technologies
• Dynamics of key technologies
• Emerging technologies and roadmaps