Sensing

Apple’s AirPods Pro use the newest MEMS microphone technology from Infineon: Sealed Dual-Membrane XENSIV^TM, found in Goertek’s microphone.

The consumer MEMS microphone market is expected to be worth $1.5B in 2024, up from $1.1B in 2019, according to the “Microphones, Microspeakers and Audio Solutions” report from Yole Développement. The main drivers are smart speakers and wireless earbuds. Two main players share the MEMS microphone market, Knowles and Goertek, with market shares of 39% and 28%, respectively.

In this dynamic context of the consumer microphone market, System Plus Consulting provides a full reverse costing study of the Infineon Sealed Dual Membrane (SDM) XENSIV^TM MEMS microphone. This microphone, sold by Goertek, was found in Apple’s AirPods Pro.

Launched in 2019, Infineon SDM XENSIV^TM is the newest Infineon MEMS microphone technology. This new MEMS microphone structure uses two movable membranes mechanically coupled by electrically insulating columns to enable a differential read-out process. In between the two membranes, where the backplate electrode is suspended, pressure is reduced. This is a sealed dual-membrane design.

The previous MEMS microphone technology from Infineon, dual backplate from 2014 used two backplates and one membrane. The 2019 sealed dual-membrane uses one backplate and two mechanically-coupled membranes. According to Infineon, this new design enables practically noise-free audio signal capturing.

This report includes a comparison between Infineon MEMS microphone technologies, dual-backplate and sealed dual-membrane, in Goertek microphones. The comparisons highlight differences in terms of structure, process, and cost.

Overview/Introduction

• Executive Summary
• Reverse Costing Methodology
• Glossary

Company Profile

• Goertek Profile and Products
• Infineon MEMS Technology

Physical Analysis

• Apple AirPods Pro Teardown
• Summary of the Physical Analysis
• Package
  • Package view and dimensions
  • Package opening
  • Package cross-section
• ASIC
  • ASIC die view and dimensions
  • ASIC delayering and main blocs
  • ASIC die process
  • ASIC die cross-section
• MEMS
  • MEMS die view and dimensions
  • MEMS bond pad
  • MEMS die process
  • MEMS die cross-section

Manufacturing Process Flow

• Overview
• ASIC Die Front-End Process and Fabrication Unit
• MEMS Die Front-End Process and Fabrication Unit
• Packaging Process Flow and Assembly Unit

Cost Analysis

• Summary of the Cost Analysis
• Yield Explanations and Hypotheses
• ASIC Die
  • ASIC front-end, wafer and die cost
  • ASIC die probe test, thinning and dicing
• MEMS Die
  • MEMS front-end, wafer and die cost
  • MEMS die probe test and dicing
• Packaged Component
  • Packaging cost per process step
  • Back end: Final test
  • Component cost

Estimated Selling Price

Comparison

• GWM1 in Apple iPhone X versus GWM1 in Apple AirPods Pro
• Infineon Dual-Backplate Versus Sealed Dual-Membrane MEMS

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