MEMS Microphone

Analysis and comparison of the design and process evolution used by Apple’s three MEMS microphone suppliers.

For microphone integration in the iPhone X, Apple has chosen the market’s top three microphone suppliers: Goertek, Knowles, and AAC Technologies.

The Apple iPhone X has four MEMS microphones: a front-facing top microphone, two front-facing bottom microphones, and a rear-facing top microphone. This layout is similar to previous iPhones, but the front-facing bottom-right microphone is now integrated in the speaker module. All four microphones share the same Apple-specific package dimensions, but with a different internal structure (number of substrate metal layers, embedded capacitance, ASIC, etc.).

In the iPhone X, we’ve observed changes to  the microphones provided by Apple’s three suppliers:

Goertek, which still relies on Infineon for die manufacturing, integrates Infineon’s technology with a double backplate, delivering a differential MEMS microphone. For the ASIC, Goertek has considerably reduced the die area by around 40% compared to the previous die.

Knowles uses the same technologies as before, but one part has a new MEMS design and another part has an existing MEMS design.

AAC uses the same MEMS microphone die as Goertek, but with a different ASIC.

Infineon is a big winner. By providing ASIC and MEMS dies to all of Goertek’s and AAC Technologies’ products, it now possesses a large share of the MEMS microphone market.

                                     

Overview/Introduction

Company Profile and Supply Chain

iPhone X – Teardown

Goertek/Knowles/AAC Technologies

Physical Analysis

• Package
  • Package view and dimensions
  • Package opening
  • Package cross-section

• ASIC Die
  • View, dimensions and marking
  • Dicing
  • Delayering and process
  • Cross-section

• MEMS Die
  • View, dimensions and marking
  • Dicing
  • Membrane and backplate
  • Anti-stiction bumps
  • Cavity
  • Cross-section

Manufacturing Process Flow

• ASIC Front-end Process
• ASIC Wafer Fabrication Unit
• MEMS Process Flow
• MEMS Wafer Fabrication Unit
• Packaging Process Flow
• Package Assembly Unit

Physical Analysis Comparison

Goertek/Knowles/AAC Technologies – Cost Analysis

• Cost Analysis Overview
• Yield Hypotheses
• ASIC Front-end Cost
• ASIC Wafer and Die Cost
• MEMS Front-end Cost
• MEMS Wafer and Die Cost
• Back-end: Packaging Cost
• Microphone Component Cost

Goertek/Knowles/AAC Technologies – Estimated Sales Price

Manufacturing Cost Comparison

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