Where is the future of MEMS?

MEMS sensors are the perceptual basis and data source of next-generation information technologies such as Internet of Things, artificial intelligence, and 5G. They have become the key foundation and important engine for economic and social development. This paper combs the MEMS concept and classification, technical advantages, application fields and market structure, discusses the status quo and characteristics of the MEMS industry chain, analyzes the opportunities and trends of industrial development, and puts forward suggestions on how to achieve industrial upgrading in China.

MEMS Overview: Principles and Classification
MEMS full name Micro Electromechanical System, the micro-electromechanical system, is an engineering technology that combines microelectronics with precision machinery. It is on the order of 1 micron to 100 micron. The core function is to convert physical signals into electrical signals that can be recognized by electronic devices. Mainly used for sensors. This requires MEMS devices to have a series of structures such as channels, holes, cantilevers, membranes, cavities, etc. to measure environmental variables, covering mechanical (moving and rotating), optical, electronic (switching and calculation), thermal, biological and other functional structures, involving many crossovers. Subject.

The development of MEMS sensors has gone through three stages: the wave of automotive electronics from 1990 to 2000 ignited the demand for MEMS sensors; the wave of consumer electronics from 2000 to 2010 promoted the development of multi-category and multi-functional integration of MEMS sensors; The wave of Internet of Things and artificial intelligence from 2010 to the present has driven the development of MEMS sensor single product volume and soft and hard.

There are many types of MEMS sensors, which can be divided into three categories: MEMS physical sensors, MEMS chemical sensors, and MEMS biosensors. Each MEMS sensor has many sub-categories, as shown in Figure 2. Common MEMS sensors are pressure sensors, acceleration sensors, micromachined gyroscopes, inertial sensors, MEMS silicon microphones, and the like. There are many types of MEMS sensors in tens of thousands, and there are many parameters between different MEMS, and there is no completely standard process.

MEMS inherits the advanced manufacturing process of integrated circuits. Compared with traditional products, it has the advantages of miniaturization, low cost, high efficiency, and mass production. The production capacity is high and the yield is high. The micrometer-scale feature size makes MEMS sensors easily adaptable to functions not possible with some traditional mechanical sensors. It is the main force of micro-sensors and is accelerating in all aspects of mass life and industrial production.

Application areas: Hundreds of flowers, wonderful
As a key entry point for obtaining information, MEMS sensors have been widely used in the fields of automotive, consumer electronics, aerospace, and biomedicine.

Automotive: In the 1990s, MEMS was first applied in the automotive industry, and automotive electronics was considered the culmination of the first wave of MEMS sensors. Benefiting from the safety regulations of the automotive industry and the wave of informationization and intelligence, MEMS sensors are rapidly developing in the automotive field. Their application directions and market demands include anti-lock braking systems for vehicles, electronic vehicle stability programs, electronically controlled suspensions, electric handbrakes, and slopes. Start assist, tire pressure monitoring, engine anti-shake, vehicle inclination measurement and in-vehicle heartbeat detection. According to relevant research data, the average car currently contains 10-30 MEMS sensors, while in high-end cars, about 30 or even hundreds of MEMS sensors are used.

Consumer Electronics: With the rapid development of consumer electronics and product innovation, this field has replaced the automobile as the largest application market for MEMS. MEMS sensors can be used in consumer electronics for motion/fall detection, navigation data compensation, game/human-machine interface interaction, power management, GPS enhancement/blind zone elimination, speed/distance counting, etc., and more applications are MEMS microphones, 3D Accelerators, MEMS RF components, GPS gyroscopes, small fuel cells and biochemical chips. The comprehensive application of a variety of MEMS sensors can increase the entertainment and intelligence of electronic devices, improve interactive performance, and greatly enhance the user experience.

Aerospace: MEMS is mainly divided into state sensors and environmental sensors in the aerospace industry. The state sensor is mainly used to monitor aircraft attitude, fuel usage, life activities, and the instantaneous position of various moving parts. Environmental sensors are mainly measured for temperature and humidity, oxygen concentration, flow rate and other aspects. By providing information about the work of the spacecraft, MEMS sensors provide the basis for fault diagnosis, decision-making, and normal flight. The recent accidents frequently occur in Boeing 737MAX aircraft that have been grounded globally. One of the main causes of the failure is that the angle of attack sensor produces a reading error, which results in the system not playing a strict protection. The importance of small sensors for aerospace safety can be seen.

Biomedical: With advances in in vitro diagnostics, drug research, patient monitoring, drug delivery, and implantable medical devices, medical devices need to rapidly improve performance, reduce costs, and reduce size. MEMS technology enables medical devices to be miniaturized, and medical testing, diagnostics, surgery and treatment processes can be more convenient, precise, and even painless. MEMS pressure sensors can detect body organ pressure levels including blood pressure, intraocular pressure, intracranial pressure, and intrauterine pressure. MEMS inertial devices are primarily used in heart disease treatment devices. MEMS image sensors are commonly used in medical imaging devices including CT scans and endoscopes. The advantages of MEMS technology in sensing and execution capabilities have led to widespread adoption in the healthcare industry.

In addition, MEMS technology is widely used in defense, industry, energy and environmental protection, providing an automated and intelligent data interface for all walks of life, empowering intelligent society. According to relevant market research data, the global MEMS market structure has the highest proportion of consumer electronics, and the largest growth space is in the biomedical field.

Market structure: fierce competition, the US and Germany companies dominate the market
Market research firm Yole Development announced the list of TOP30 global MEMS product sales in 2018, as shown in Figure 4. The data shows that total sales in 2018 increased by 5% from 2017 to $10.3 billion (about RMB 70.04 billion). The sales of TOP30 companies account for about 90% of the global MEMS market.

From the perspective of the head enterprises, the "Shuangbo (Botong + Bosch) killing effect" appeared. Both companies' revenues exceeded $1 billion, significantly leading the follow-up vendors and forming an oligarchy. TOP1 Broadcom has grown rapidly since 2013 and has been famous for trying to acquire Qualcomm. Broadcom is mainly engaged in RF MEMS products, and the rapid popularization of smart phones has led to an increase in the price and price of RF MEMS products, which has played a decisive role in maintaining Botong's first position. The second-ranked Bosch is a sports MEMS product that is dually deployed in the automotive and consumer electronics arena. According to the survey, almost all new cars will be equipped with Bosch's five MEMS, and about 50% of the world's smartphones will be equipped with at least one Bosch MEMS. At the same time, Bosch has its own MEMS manufacturing base to optimize manufacturing costs. It can be expected that the "fight" between Broadcom and Bosch will intensify in the future.

From the perspective of the neck enterprises, the products are diversified and the competition is fierce. TOP3's STMicroelectronics not only provides MEMS products for automotive, industrial, and civil applications, but also manufactures MEMS for other companies. As a veteran manufacturer, the market share of TOP4 Texas Instruments has been declining year by year, and it is actively exploring new markets such as vehicles. TOP5's QROVO is also positioned on the RF MEMS track and is currently actively addressing delivery delays. As a TOP6 Hewlett-Packard company with the same revenue of more than $500 million, it is growing with its MEMS inkjet head. In addition, TOP30's other products also cover acoustic MEMS (Lou Shi, Goer shares, AAC), radiation MEMS (FLIR, ULIS), bio-MEMS (OMRON), image MEMS (Canon, Sony), And they have achieved leapfrogging and catching up on their own tracks.

Two Chinese companies are on the list, namely TOP11's Gore shares (GCERTEK) and TOP23's AAC (AAC). The two companies focus on acoustic MEMS products and system integration, ranking no change from 2017. However, due to the weak sales of smartphones in the downstream market in 2018, the two companies did not perform well in 2018. It is expected that in the next two years, driven by the demand for smart speakers, AR/VR and other products, we can expect the performance of the two companies.

Due to the wide variety of MEMS sensor products and the wide range of application requirements, each company has its own market segment and a certain living space. Overall, the MEMS sensor market is dominated by foreign companies.

Industry chain: China's design and foundry need to be strengthened, and the testing and testing links are competitive.
Similar to the integrated circuit industry, the MEMS industry chain is also divided into three major links: upstream design - midstream manufacturing - downstream packaging testing. As shown in Figure 5, the industry division of each link is clear. Most of the major manufacturers in the MEMS industry are based on Fabless, such as Broadcom and Lou. At the same time, IDM manufacturers also vertically participate in all aspects of the entire industry chain, which can improve the overall competitiveness of the brand.

The domestic MEMS industry chain is complete in layout, but in general, the industry is still in the initial stage of development. The products have huge gaps in performance indicators such as accuracy and sensitivity, and the application scope is limited to the traditional field.

Design link: The company has certain innovation ability, but the business overlap is high, the product positioning is low-end, and the overall revenue of the industry is small. MEMS design belongs to the high value-added link of the industrial chain. Domestic enterprise products are mainly based on mechanical sensors, and are at the low-end level in the market. The sales of enterprises are generally small. Except for the revenue of 2-3 billion yuan per year by Meixin Semiconductor, the income of a few companies such as Suzhou Minxin, Wuxi Core Aowei and Nanjing Gaohua is 10 million. The rest of the enterprises are Millions or not yet started product sales.

Foundry link: The capacity of the technology authorized construction line has not yet been opened, and the pure MEMS foundry is still in the industrial introduction period. MEMS foundry can be divided into three types: pilot line, IC foundry and MEMS professional foundry. The pilot test line is mainly based on universities and research institutes. As an industrial common technology research and development platform, it does not aim at profitability and has limited production capacity. IC foundry MEMS business is in its infancy, and its capabilities are relatively weak. Domestic design companies with a certain scale basically choose foreign foundries. In terms of MEMS professional foundry, at the end of 2015, domestic manufacturer Naiwei Technology acquired Silex Microsystems, a Swedish MEMS foundry, to master the world's leading MEMS foundry technology. In addition, a number of companies such as Hanwang Microelectronics and Xi'an Lide Microsystem have also entered the field of professional MEMS foundry.

The testing and testing process: the outsourcing MEMS chip packaging and testing mode is relatively mature, and the enterprises mainly based on acoustic MEMS products have certain international competitiveness. Although domestic MEMS foundry lags behind international manufacturers, packaging and testing technology started earlier, has achieved good results, and is internationally competitive. Among them, Goer shares and AAC Technologies, which use MEMS microphones as the main products, have a certain premium space because the business model is to purchase the IP of the MEMS products of foreign design manufacturers and commission the OEM to complete the package testing and sales of the products themselves. It is now in the global MEMS TOP30 camp.

Development trend: the market has a high degree of prosperity, and the product evolves toward the “four modernizations”
In terms of market size, benefiting from the rapid development of new industries such as artificial intelligence, 5G, and Internet of Things, it is expected that the MEMS industry will grow rapidly in the future.

Major MEMS companies grew slightly below expectations in 2018, reflecting a modest adjustment in the semiconductor industry. However, with the rapid development of emerging industries such as artificial intelligence, 5G, and Internet of Things, the market demand for consumer electronics and smart cars has gradually recovered, and new products, new functions, and new fields have been expanding. According to Yole, the MEMS market will be between 2018 and 2024. Significant growth during the year: the compound annual growth rate of overall market revenue was approximately 8.3%, and the compound annual growth rate of shipments was approximately 11.9%.

The expected growth of each segment is shown in Figure 6. Overall, traditional products such as inertial MEMS, pressure MEMS and inkjet head MEMS have limited room for growth; oscillators, fingerprints, thermoelectric MEMS and other penetration rates still have room for improvement, and the future prospects are promising.

From the perspective of technology and product trends, MEMS sensors are evolving into four categories: intelligent, integrated, low-power, and miniaturized.

Add signal processing to achieve intelligence. As the "sensing hub" of electronic products, modern sensors can also undertake functions such as automatic zero adjustment, calibration and calibration by adding micro-control units and corresponding signal processing algorithms to realize the intelligentization of terminal equipment.

The sensor presents a number of features that are highly integrated and combined. As design space, cost and power budgets become tighter, integrating multiple sensitive components on the same substrate and making a versatile combinatorial MEMS sensor capable of detecting multiple parameters is an important solution.

The demand for low power consumption of sensors is increasing. With the rapid growth of sensing demand for applications such as the Internet of Things, the number of sensors used has increased dramatically and energy consumption has doubled. The need to reduce MEMS power consumption and enhance endurance will be accompanied by the development of sensors, and it is becoming increasingly strong.

Miniaturization is irreversible and MEMS is evolving to NEMS. Similar to MEMS, NEMS (Nano Electromechanical Systems) is a micro-nano system technology that focuses on the nanoscale field, but with a smaller size. With the miniaturization and variety of terminal devices, the evolution of MEMS to smaller sizes is the trend of the times.

to sum up
As an important direction and breakthrough of "More than Moore", and in the hotspot application of artificial intelligence, Internet of Things and other hotspot applications, the MEMS industry is currently in a period of great strategic opportunities.

From the perspective of the industrial chain, there is a lack of independent research and development and industrialization capabilities for key technologies related to MEMS. In terms of enterprise scale, there are about 200 MEMS sensor manufacturing enterprises in China in 2018, most of which belong to start-up small and medium-sized enterprises. From the perspective of product structure, domestic MEMS companies have significant gaps in business scale, technology level, product structure, etc., and their main products are concentrated in the low-end traditional areas.

Although China's MEMS sensor manufacturers face many challenges, there is huge room for domestic substitution in the fields of upstream design, midstream manufacturing, and downstream packaging and testing. China's MEMS development has a long way to go. China should be guided by huge market applications, constantly bridging the talent gap, judging and grasping the future trend, anchoring the road of independent innovation, and achieving large-scale rise and catch-up.