MEMS IMU/Combo

The market’s thinnest 6-Axis IMU!

With the introduction of Apple’s latest products in Q4 2017, Bosch Sensortec is now the undisputed leader in MEMS IMU for consumer applications. Indeed, Bosch completely crushed the competition by replacing InvenSense inside the newest iPhone 8 and iPhone X, and supplanting STMicroelectronics for the Apple Watch Series 3. These three new design wins give Bosch hundreds of millions of unit sales per year.

This new Bosch Sensortec component is likely a custom 6-axis IMU made specifically for Apple. It is exactly the same component found inside the iPhone 8, iPhone X, and Apple Watch Series 3. One major improvement is the incredibly thin profile achieved by Bosch, with a total thickness of only 0.6mm compared to 0.9mm for the industry standard. This thickness was probably an Apple request in order to fit with the small form factor of the Apple Watch Series 3’s cellular functionality. To achieve this low profile, Bosch changed the packaging structure used for its preceding product, the BMI160.

On the design side, Bosch Sensortec made significant changes – particularly for the accelerometer, where the old single-mass structure was abandoned for a new structure achieving better sensing properties. The micromachining manufacturing process, unchanged by Bosch Sensortec for many years, was also revised, with a new process for both accelerometer and gyroscope.

Finally, a new ASIC die was designed to fuse the data from the accelerometer and gyroscope, and probably to deliver even lower current consumption and other functionalities.

This report includes a detailed physical analysis, with process description and manufacturing cost analysis. A complete comparison with Bosch Sensortec’s BMI160 is also provided, along with a comparison with InvenSense and STMicroelectronics’ latest 6-axis IMUs.

                  

Overview /Introduction

• Executive Summary
• Reverse Costing Methodology

Company Profile

• Bosch Sensortec
• Consumer IMU Market
• Apple iPhone X, iPhone 8, and Watch Series 3 Teardown

Physical Analysis

• Synthesis of the Physical Analysis
• Package
  • View and dimensions
  • Opening
  • Wire bonding process
  • Cross-section

• ASIC Die
  • ASIC die view and dimensions
  • ASIC delayering and main blocs
  • ASIC die process
  • ASIC die cross-section

• MEMS Accelerometer Die
  • MEMS die view and dimensions
  • MEMS die cross-section
  • MEMS accelerometer process

• MEMS Gyroscope Die
  • MEMS die view and dimensions
  • MEMS die cross-section
  • MEMS gyroscope process

• Physical Comparison
  • Bosch IMU sensor evolution
  • Comparison with IMUs from InvenSense and STMicroelectronics

Sensor Manufacturing Process

• ASIC Die Front-End Process and Fabrication Unit
• MEMS Accelerometer Process and Fabrication Unit
• MEMS Gyroscope Process and Fabrication Unit
• Packaging and Final Test Fabrication Units

Cost Analysis

• Synthesis of the Cost Analysis
• Yields Explanation and Hypotheses
• ASIC Component
  • Wafer front-end cost, probe test, thinning and dicing
  • ASIC wafer and die cost

• MEMS Accelerometer Die
  • Wafer front-end cost, probe test and dicing
  • Accelerometer wafer and die cost

• MEMS Gyroscope Die
  • Wafer front-end cost, probe test and dicing
  • Gyroscope wafer and die cost

• LGA Packaged Component
  • Back end: LGA packaging cost
  • Back end: final test
  • Component cost

Sales Price

• MEMS Packaging: Reverse Technology Review
• BOSCH Sensortec BMF055
• Gas and Particle Sensors 2018
• Miniaturized Gas Sensor Comparison 2018
• MEMS Pressure Sensor Comparison 2018
• Apple iPhone X Special Offer
• InvenSense ICM-20789: High Performance 6-Axis Motion Sensor and Pressure Sensor Combo
• Bosch BME680 Environmental Sensor with Integrated Gas Sensor
• 6-Axis OIS IMUs
• InvenSense ICM-30630