Media Focus: Minshin Shares: A Longer-Term View of the Development of the Domestic MEMS Sensor Industry

MEMS is a miniature device or system that integrates microsensors, microactuators, micromechanical structures, signal processing, and interfaces. It is an innovative technology that has emerged along with nanotechnology. It has significant characteristics such as miniaturization, integration, intelligence, low cost, and good consistency.

To date, there are many types of MEMS sensors, including inertial sensors, pressure sensors, microphones, temperature and humidity sensors, and radio frequency sensors. On Minxin Shares' new official website, we can see that the company currently has six major categories: acoustic sensors, pressure sensors, inertial sensors, mechanical sensors, flow mechanical sensors, and thermoelectric pile infrared sensors. Among them, MEMS acoustic sensors are one of Minxin Shares' current main shipped products.

Minxin Shares Deputy General Manager Zhang Chenliang accepts an exclusive interview

Currently, Minxin Shares already has several products in the MEMS microphone field, featuring high reliability, high-performance indicators, high consistency, low defect rate, low rework rate, and full-industry-chain localization. Zhang Chenliang said, "In recent years, there have been two main development directions for MEMS microphones. The first is higher SNR (signal-to-noise ratio). Now the SNR of MEMS microphones has reached 68-72dB, with the mainstream being 62-65dB. In the future, it may reach 75dB or higher. This is one direction; the second is a higher AOP (maximum sound pressure level, unit 10% THD@1kHz). The previous range was 120-123, gradually reaching 125-128, and continuing to develop towards 130-132 and above."

"In the past two years, publicly available data clearly shows that Minxin Shares has a high proportion of R&D investment in revenue. The SNR and AOP of MEMS microphones are the technical directions we continue to invest in. For example, in terms of AOP, we have achieved mass production of 127 and 130 levels." Zhang Chenliang pointed out, "In the past, the MEMS sensor industry, including MEMS microphones, was led by international giants such as Knowles, Bosch, and ST in terms of technological development. The domestic MEMS sensor industry started late and mainly followed in the early stages, with a technological gap of basically 2-3 generations. Now, the gap between us and international giants is getting smaller and smaller, and in some segmented market applications and some parameters, we have begun to lead the industry."

MEMS microphones are Minxin Shares' flagship products. In the industry statistics data of 2018 and 2019, Minxin Shares was among the top ten manufacturers globally. Currently, in terms of shipments, Minxin Shares has become the world's fourth-largest MEMS microphone manufacturer. As technology and processes gradually mature, MEMS sensors have a clear trend of replacing traditional sensors. The replacement of ECM microphones by MEMS microphones is a testament to this. "Around 2014, Minxin Shares began to promote the replacement of ECM microphones with MEMS microphones by mobile phone ODM manufacturers." Zhang Chenliang said.

Regarding the subsequent development of MEMS microphones, he believes that in addition to continuous optimization of products, the integration of MEMS microphones and software is an important trend.

Indeed, from the current development status, creating a highly integrated solution of MEMS microphones and algorithms is an inevitable trend. This requires high integration of MEMS microphones and algorithms to adjust better user experience effects for specific application scenarios, such as ANC applications, directional applications, and multi-microphone noise reduction applications. This also reflects the ability of MEMS microphones to cope with the intelligence of terminal devices.

During the interview, the EEWORLD reporter learned that Minxin Shares won the 2021 Wu Wenjun Artificial Intelligence Science and Technology Award Third Prize for Chip Project, becoming the only award-winning unit in the MEMS industry. Zhang Chenliang responded to this by saying, "Sensors, including MEMS microphones, are responsible for data acquisition in the Internet of Things. As the amount of data continues to increase, the number of data acquisition nodes will also gradually increase, so sensors have broad development prospects. But the sensor is just a foundation. How to collect data? What data to collect? These require the integration of sensors and algorithms to achieve. The '2021 Wu Wenjun Artificial Intelligence Science and Technology Award' precisely proves Minxin Shares' technical strength in algorithm integration and intelligent sensing."

In the list of Minxin Shares' MEMS acoustic sensors, in addition to MEMS microphones, there are also bone conduction sensors. Bone conduction is the process by which sound is transmitted to the inner ear through the jawbone. During the transmission process, the sound is transmitted to the cochlea through the jawbone, bypassing the eardrum, resonating with the relevant parts according to the audio frequency, and finally becoming a nerve signal in the brain. Minxin Shares mentions in its product introduction that bone vibration sensors are not sensitive to airborne sound signals and have a natural inhibitory effect on airborne sound signals. Therefore, the call noise reduction algorithm is simpler and more natural, noise suppression is more effective, and better uplink call effects can be provided.

Zhang Chenliang introduced, "Minxin Shares is one of the first domestic companies to have bone conduction sensor technology. This is an incremental market, mainly targeting applications such as earphones and AR/VR. Subsequent development requires the concerted efforts of the entire industry chain upstream and downstream to promote market applications."

Minxin Shares was founded in 2007 and is one of the earliest companies in China to conduct MEMS sensor research, so it has a deeper understanding of industry development. According to relevant statistical data released by the CCID Consulting, in 2020, the scale of China's MEMS market reached 70.54 billion yuan, an increase of 10.76 billion yuan compared with 2019, a year-on-year increase of 18%. It is estimated that the scale of China's MEMS market will reach 86.213 billion yuan in 2021, a year-on-year increase of 22.2%.

Zhang Chenliang said, "Minxin Shares is the first MEMS chip stock in China and is one of the earliest companies in China to enter this industry. However, the objective fact is that the domestic MEMS sensor industry started relatively late. Minxin Shares has experienced the entire process of domestic MEMS sensors from nothing to something, from immature to gradually mature. In the first few years, there were very few domestic peers."

He said with special emotion, In fact, in terms of cultivating the domestic MEMS industry chain, Minshen shares, as a small company, is leveraging a large industry.

To date, Minshen shares has covered six major product ecosystems and has completed the vertical integration of MEMS sensors from design to manufacturing and packaging. In terms of wafer foundry, Minshen shares has a deep business relationship with Huarun Microelectronics and SMIC; in terms of chip packaging, Huatian Technology is an early partner of Minshen shares. At the same time, Minshen shares has four subsidiaries, including Suzhou Desbei, a wholly-owned subsidiary mainly engaged in the packaging and testing of MEMS sensors; Suzhou Xinyiwei, a wholly-owned subsidiary engaged in ASIC chip R&D and design; Kunshan Lingke Sensing, a wholly-owned subsidiary whose main products are sensor modules; and Zhong Hong Weiyu, a holding company that develops smart Internet of Things solutions centered on smart sensors. In addition, according to Zhang Chenliang, the company has also indirectly participated in the investment and construction of the MEMS pilot production line of Suzhou Yuanxin, further enhancing its capabilities in MEMS process R&D.

MEMS sensors are not only highly dependent on design, but also highly dependent on manufacturing. MEMS sensors are unique products, so they require special processes. Through cooperation with wafer fabs and investment in packaging production lines, we can gradually refine our product design, gradually differentiate our products, achieve industry-leading levels, and impact the high-end market. Zhang Chenliang said, "MEMS is a special process, and moving towards IDM vertical integration is the development trend of the industry."

According to his description, Minshen shares has currently achieved diversified product development, completed vertical integration of the industry chain, and has the ability to impact the high-end market. For Minshen shares' current flagship product, MEMS microphones, the high-end market means entering the supply chain of leading brands of consumer electronics products such as mobile phones and smart speakers. "Minshen shares has completed product introduction into the supply chains of some brand manufacturers, but volume production still requires a process. Brand customers will not immediately give large order quantities, but will first have an evaluation period. Minshen shares is in this evaluation period, and volume production is only a matter of time. We have already crossed the threshold of brand customers, and the next focus is to accelerate the progress of cooperation between the two sides." Zhang Chenliang said in the interview.

With the gradual improvement of the domestic MEMS sensor industry, the ability of MEMS to "chipize" sensors has been widely recognized. Therefore, when discussing the development trend of domestic sensors, in addition to the past integration, miniaturization and intelligence, sometimes "MEMSization" is also added.

In this regard, Zhang Chenliang believes that, "This view puts too big a 'hat' on the MEMS industry. The scale of the global MEMS sensor industry is only a small part of the entire semiconductor industry. MEMS is a way of implementation, but it is not applicable to all sensors. In recent years, with the increasing popularity of semiconductors, MEMS sensors have also experienced overheating, with many companies entering this track. However, MEMS sensors are graded, and the level of the product corresponds to the level of the customer. Low-end market competition will be very fierce, and it can even be said that involution has occurred. Involution is very difficult to make money. The key is to enter the high-end market and enter the supply system of brand customers. This depends on whether related enterprises can continue to invest and create high-end products, and then enter the high-end market."

He particularly emphasized the need to take a longer-term view of the development of the domestic MEMS sensor industry.

Here, he uses the development of Minshen shares as an example, which also responds to the questions about the year-on-year decline in Minshen shares' net profit in the previous financial report. The following text is compiled from the interview content:

Minshen shares is a company that focuses on R&D. After completing its listing on the Science and Technology Innovation Board, the company has further increased its investment in R&D, which can be seen from publicly available data. It has also strengthened the incentives for core technical personnel. Minshen shares has cultivated many MEMS sensor-related talents, and what it needs to do is to retain people. The company has hired a full-time HR with experience from large factories to build a talent system and complete the construction of the talent echelon.

With the continuous launch of various new products by Minshen shares, other types of MEMS sensors of Minshen shares will gradually form a combined competitive advantage with acoustic sensors. The launch of these products proves that Minshen shares has the ability of industrial diversification, and has the opportunity to provide differentiated solutions, enhancing the opportunity and stickiness of developing with brand customers, and ultimately the revenue share of MEMS microphones will gradually decrease. Minshen shares is defined as a technology platform enterprise. The concept of a platform requires research and reserves of MEMS-related technologies. Companies with technical accumulation awareness are looking at long-term development.

In terms of the industry chain, Desbei's own packaging capacity and Yuanxin's R&D and manufacturing capacity of the wafer pilot platform have enhanced Minshen shares' flexibility in special project initiation, and thus have stronger autonomy in product R&D.

Some of these investments have short-term effects, some have medium-term effects, and some have long-term effects. In other words, these investments may reduce Minshen shares' net profit level in the short term, but will gradually show the aggregation effect of Minshen shares in terms of products, platforms and industry chains.

“We welcome more local companies to participate in the healthy competition of the MEMS sensor industry and work together to make the domestic MEMS cake bigger and stronger!” Zhang Chenliang said.