STMicroelectronics, TDK InvenSense, and Bosch Sensortec MEMS IMUs… all you need to know from the technological choices to the design wins with big smartphone OEMs

“The MEMS inertial sensor market focused on IMUs in smartphones is mainly represented by three leading MEMS device manufacturers: STMicroelectronics, TDK InvenSense, and Bosch Sensortec.” asserts Audrey Lahrach, Technology & Cost Analyst, MEMS, Sensors & Displays at Yole SystemPlus, part of Yole Group. She adds: “Those players have made different technological choices in an ultra-competitive sector to reach their own objectives. As an example, we identified different wafer assembly processes such as glass frit, eutectic bonding combined, or not, with fusion bonding”.

Yole Intelligence, part of Yole Group has been investigating the MEMS industry for a while and collaborates closely with Yole SystemPlus to analyze the growth of the MEMS market, the strategies of the MEMS companies, and the evolution of the technologies. In its dedicated MEMS report, Status of the MEMS Industry 2021, the market research & strategy consulting company forecasts a US$838 million consumer IMU market in 2026 with a 5% CAGR_2020-2026.
Audrey Lahrach from Yole SystemPlus comments: “This growth will be driven by an increasing integration rate of MEMS IMUs in smartphones & wearables. Moreover, the increasing replacement of stand-alone MEMS accelerometers and gyroscopes with IMUs will contribute to this growth.”

In this dynamic context, the reverse engineering and costing company Yole SystemPlus releases today a comprehensive analysis fully dedicated to inertial sensors for smartphone applications: the Mobile Inertial Sensors Comparison 2021 report. For this report, Yole SystemPlus looked at a sample of 114 smartphones. It extracted the MEMS inertial sensors from each smartphone and analyzed each IMU found in-depth. The sample included 53 smartphones released in 2019, 54 smartphones in 2020, and 7 in 2021. With this approach, System Plus Consulting’s analysts identified the reference of each sensor for each smartphone and, underlying that, the devices’ manufacturer.

With this new report, Yole SystemPlus delivers a comparative review of the most common IMU references for smartphones. The company examined the dimensions and internal structures of their packages, MEMS arrays, and ASICs, as well as their die sizes and cross-sections of the packages. Its objective is to present a comprehensive review of MEMS inertial sensors in smartphones, the technical choices made by each MEMS device manufacturer, and make the link with the relevant OEMs.

The comparison has been further developed at the IMU manufacturing process level between manufacturers, as well as between the different technologies selected by the same manufacturer and integrated into the smartphones comprising Yole SystemPlus’s sample. Lastly, a comprehensive technology and cost analysis is presented of the most common references found in our sample, including the MEMS, the ASIC, and the packaging.
In addition, this report features a teardown analysis with a package opening and a MEMS die opening for the components that integrate single MEMS (only a gyroscope or an accelerometer).
Yole SystemPlus’s sample also reveals that STMicroelectronics is the design wins’ with 3 main different references and is the leading MEMS device manufacturer with half of the total components. TDK InvenSense and Bosch Sensortec occupy the second and third places, with 27% and 17%, respectively.

To conclude, these top 3 companies manufactured 94% of the total components integrated into the smartphone sample analyzed by Yole SystemPlus since 2019.
The most important observation in Yole SystemPlus’s report is MEMS die size reduction for STMicroelectronics in their LSM6DSO reference, states Audrey Lahrach from System Plus Consulting.
For TDK Invensense, many things have changed. Therefore, Yole SystemPlus highlights in its report the significant evolution in the processing of its ASIC part. The MEMS device manufacturer has reduced its technological node by switching to 90nm in its last reference and integrating layers of copper metal while keeping aluminum for the eutectic wafer bonding Al-Ge. Thus, the company assembles the ASIC and the MEMS at the wafer level to get a single ASIC/MEMS die.
From their sides, the two companies, STMicroelectronics and Bosch Sensortec, decided to combine their two dies in their LGA Package, the ASIC on one side and the MEMS on the other. Bosch Sensortec placed its gyroscope and its accelerometer on the same chip in one reference, BMI270. It aimed to remove one die in the component, which impacted the size of the MEMS chip, at the same time, compared to its previous one…Further details in the Mobile Inertial Sensors Comparison 2021 report.