Technology, Process and Cost
STMicroelectronics Proximity Sensor and Flood Illuminator
By Yole SystemPlus —
New Time of Flight and Illumination Device from the Apple iPhone 12.
Overview / Introduction
Company Profile
- STMicroelectronics
- FlightSenseTM Technology
Physical Analysis
- Summary of the Physical Analysis
- Package
- Package view and dimensions
- Package opening: overview, wire bonding, flood illuminator
- Package cross-section: adhesives, ceramic substrate, PCB substrate diffuser, filters, FOV, heat sink
- VCSEL #1 & #2 Die
- Die view and dimensions, overview and cavity, cross-section and process characteristic
- VCSEL Driver Die
- Die view and dimensions, overview and marking, delayering and main block ID, cross-section and process characteristic
Comparison iPhone X and iPhone 12 Proximity Sensor
Manufacturing Process
- SPAD Detector Die Front-End Process and Fabrication Unit
- VCSEL Driver Die Front-End Process and Fabrication Unit
- VCSELs Die Front-End Process and Fabrication Unit
- OLGA Packaging Process and Fabrication Unit
Cost Analysis
- Summary of the Cost Analysis
- Yield Explanations and Hypotheses
- SPADs Detector and VCSEL Driver Die
- Die front-end cost, wafer and die cost
- VCSEL Dies
- Die front-end cost
- Die front-end cost per process step
- Die wafer and die cost
- Component Cost
- Proximity Sensor Selling Price
This full reverse costing study has been conducted to provide insights into technology data, the manufacturing cost and selling price of the STMicroelectronics Proximity Sensor and Flood Illuminator in the Apple iPhone 12.
Located in the front above the main speaker, the proximity sensor and flood illuminator use optical Land Grid Array (LGA) packaging. The device is a custom version for Apple, coming after STMicroelectronics also released a custom proximity sensor for the iPhone X. While being 15% smaller than the previous version overall, the new version’s flood illuminator is twice as large. The sensor is still based on FlightSenseTM technology.
The flood illuminator has a larger Vertical Cavity Surface Emitting Laser (VCSEL) die and VCSEL driver die. The diffuser is more sophisticated with a complexity close to a diffractive optical element.
To reduce the package size with larger components, STMicroelectronics has developed a 3D package with two stacked Printed Circuit Boards (PCBs). The 3D package manages the heat dissipation of the flood VCSEL thanks to a ceramic substrate, solder balls and PCB design.
This report analyzes the complete microsystem from the VCSEL illuminator of the proximity sensor manufactured by Trumpf to the VCSEL of the flood illuminator manufactured by Lumentum. It also analyzes the two integrated circuits with VCSEL driver from Texas Instruments and the Single Photon Avalanche Diode (SPAD) developed by STMicroelectronics. It includes analyses of the package, the diffuser and the filters with optical and Scanning Electron Microscopy pictures and Energy Dispersive X-ray analyses of the main semiconductor components. The report also includes a complete cost analysis and price estimation of the device based on a detailed description of the package, the Time-of-Flight detector, and the two VCSELs.
The report features also a complete technology comparison with the proximity sensor from the Apple iPhone X.
Complete teardown with:
- Explanation of device operation
- Detailed optical and SEM photos
- Precise measurements
- Materials analysis
- Manufacturing process flow
- Supply chain evaluation
- Comparison between proximity sensor of iPhone 12 and iPhone X
- Manufacturing cost analysis
- Estimated sales price