Central media attention! Economic Daily: Suzhou Minshen focuses on MEMS sensor research and development, using innovation to "perceive" the world

What are MEMS (Micro-Electro-Mechanical Systems) sensors? A reporter experienced their magic at Suzhou Minsic Microelectronics Technology Co., Ltd. (hereinafter referred to as "Minsic"). In a room filled with various noises, simply speaking a command would "wake up" a seemingly "sleeping" smart speaker, prompting it to receive instructions.

　　“The advent of MEMS acoustic sensors has transformed speakers from simple music players into interactive smart terminals,” Minsic's founder and president, Li Gang, explained. MEMS sensors utilize semiconductor manufacturing technology to create microelectromechanical systems on silicon wafers capable of collecting external signals. Their miniaturization, low power consumption, and high reliability make them widely applicable in consumer electronics, automotive electronics, and medical fields.

　　In Minsic's product showroom, adorned with patent certificates, the reporter saw that the MEMS microphone sensor for wireless Bluetooth earphones was only the size of a sesame seed.

　　“Our cumulative MEMS sensor chip shipments have reached 1 billion units,” Li Gang said. As one of the earliest MEMS companies in China, Minsic has, through 15 years of continuous R&D investment, completed the basic research and core technology accumulation in MEMS product chip design, wafer manufacturing, and packaging and testing, achieving independent and controllable production of MEMS sensors across all production stages.

　　MEMS acoustic sensors originated in the early 20th century. Li Gang, who was then studying MEMS technology in the microelectronics major at Peking University, became extremely interested in them. In 2007, Li Gang led a startup team whose MEMS sensor project was selected for the Suzhou Industrial Park's first Science and Technology Leading Talents Program. The same year, preparations began for the establishment of Minsic.

　　Li Gang said that during the rise of smartphones, people's demands for phone functions increased. Besides clear calls, they wanted recording and camera functions, traditional microphones could no longer meet these needs, and MEMS sensors became the market's "new favorite." Minsic keenly sensed this market potential and decided to develop the product.

　　However, Minsic's journey was not smooth. “When we went looking for product development platforms and industrial supply chains with our design ideas, we were repeatedly turned away,” Li Gang said. This was because MEMS sensors, designed and structured in three-dimensional space, had low output and specialized processes, so domestic comprehensive semiconductor companies were unwilling to invest in production at the time.

　　Minsic simultaneously promoted its R&D ideas to companies in the industry and maintained its survival by designing chips. In 2008, Minsic's R&D team received assistance from the Suzhou Institute of Nano-Tech & Nano-Bionics, Chinese Academy of Sciences, producing its first batch of MEMS acoustic sensor chips on its R&D platform.

　　Li Gang frankly admitted that the difference between laboratory samples and mass-produced industrial products is not only in quantity but also in product quality and stable performance.

　　“Our initial product yield rate was only 30%, urgently needing process correction through mass production,” Li Gang said. At that time, the state included new electronic components in high-tech industry development projects, providing strong policy and financial support, leading some domestic semiconductor manufacturers to turn their attention to the production of MEMS sensors.

　　Subsequently, China Resources Microelectronics Co., Ltd. invested in the construction of a MEMS sensor production line and cooperated with Minsic. “Both companies assembled elite teams, and R&D personnel spent almost every day on the production line, observing test results, correcting processes and parameters, and tackling challenges with an unyielding spirit,” said Minsic's R&D director, Sun Kai. In 2012, the company's first MEMS acoustic sensor using independently developed chips achieved mass production, and due to its high quality, quickly secured a place in the market.

　　Currently, Minsic has become a supplier of MEMS acoustic sensors for many well-known brands. Its products are used in smartphones, tablet computers, wearable devices, and smart home consumer electronics, and are continuously expanding into automotive and medical fields.

　　Entering Minsic's acoustic laboratory, Sun Kai and the R&D team members were using an acoustic analyzer to test the noise of high signal-to-noise ratio products using a simulation mouth.

　　“Look, our sensor's signal-to-noise ratio has reached 70dB (decibels), and the AOP (maximum sound pressure level) has reached 135, which is at the industry-leading level,” Sun Kai said excitedly, looking at the data displayed on the acoustic analyzer.

　　“Signal-to-noise ratio refers to the ratio of signal to noise. The higher the signal-to-noise ratio, the less noise mixed in the signal, and the better the sound quality; the sound pressure level refers to the highest sound level that the microphone can handle before distortion. The higher the sound pressure level, the higher the sound it can handle,” Sun Kai said. While ensuring clear sound quality, MEMS acoustic sensors must improve signal-to-noise ratio and maximum recording sound pressure to achieve functions such as longer-range voice control and sound localization.

　　To accelerate R&D speed and product iteration, Minsic has established multiple R&D teams, continuously conducting "brainstorming" sessions for each product, performing thousands of experiments, and continuously striving for industry leadership. Li Gang told the reporter that the company has customized and developed more than 80 types of high-frequency, wide-frequency, and miniaturized special MEMS acoustic sensors in recent years, meeting various market needs.

　　Minsic's large product output stems from its relentless R&D investment. The company's R&D investment was 35,670,400 yuan in 2019, 42,043,400 yuan in 2020, and 75,618,600 yuan in 2021; R&D personnel accounted for more than 33% of the company's total employees; and R&D expenses accounted for more than 21% of operating revenue.

　　In its 15 years of operation, Minsic has adhered to innovation and R&D. Currently, it possesses a multi-category product line with independent R&D and intellectual property rights, gradually growing into one of the few domestic companies that have mastered the design and manufacturing processes of multi-category MEMS sensors.

　　“In 2021, Minsic's invention and utility model patent numbers increased by 150% and 140% respectively compared to 2020, and the number of R&D personnel increased by 40% year-on-year; in the first half of 2022, the number of invention patents authorized was 1.4 times that of the whole year of 2021.” In Li Gang's view, to maintain vitality, companies cannot rely on imitation alone; they must achieve breakthroughs through R&D innovation, constantly surpass themselves and their competitors, to win the future.

　　The manufacture of a MEMS sensor involves core stages such as chip design, wafer fabless manufacturing, packaging, and testing. “If we completely rely on external industrial chains, startups will find it easy to start but difficult to scale up, and cost and scale advantages will be difficult to achieve, and core competitiveness will be lost, leading to unavoidable ‘homogenization’ competition,” Li Gang said. Because the production process of MEMS sensor chips is highly customized, the production process needs to be developed on demand, and the manufacturing, packaging, and testing stages are particularly important.

　　Li Gang vividly remembers a packaging parameter error incident from several years ago. On an outsourced sealed test production line, a parameter error caused the microphones already installed in the phones to risk failure. "Acoustic sensors are different from other components; once they fail, the phone becomes unusable. If the microphone malfunctions, the phone's value needs to be compensated according to the price, which is unbearable for a startup company. Products must be well-designed, but also well-manufactured, well-packaged, and well-tested." said Li Gang.

　　Fortunately, this batch of products did not experience widespread failures. However, this served as a wake-up call for the company, making them realize the necessity of independent and controllable industrial chains.

　　In 2019, Minshun invested in and established a wholly-owned subsidiary focusing on MEMS packaging. "Currently, our phase-one packaging and testing factory has been put into operation, with a monthly production capacity of 40 million MEMS sensor packages. Next year's first half will see the launch of our phase-two factory, and the monthly packaging capacity is expected to increase to 100 million." said Li Gang.

　　Today, Minshun has successfully joined the ranks of leading domestic MEMS companies, with applications spanning consumer electronics, medical devices, industrial control, and automotive electronics. "Over the years, the company has survived the intense market competition by entering the mid-to-low-end application market. Currently, the company is striving to enter the supply chain systems of internationally renowned consumer electronics brands." Li Gang said that Minshun is accelerating its pace in research and development innovation and continuously improving and filling gaps in its entire industrial chain to ensure its supply capacity keeps pace with demand, thus leveraging the strengths of its supply chain.