VCSEL Array Die Bonding

99.8%

Overall Yield

<100μm

Chip Thickness

<0.15μm

Chip Size

Process Challenges

The customer specializes in VCSEL chip (GaAs substrate) R&D and manufacturing, producing emitter devices for automotive LiDAR. Chip size is below 0.15 mm, thickness below 100 μm, supplied on blue film. Multiple VCSEL array chips are bonded as a whole onto a PCB substrate.

Small-chip Pickup: Ejector pin operations easily cause blue film tearing and chip damage/fracture
Small-chip Recognition: Vision recognition stability for tiny array chips is poor, prone to recognition failures
Strict Dispensing Requirements: Sidewall fillet must cover over 70%, with full perimeter wet-out; actual production is prone to adhesive pullback

Solution

Leveraging the ZX2200 Multi-Chip Flexible Production Platform, the following optimizations were implemented to address the process challenges:

For blue film scratching and chip ejector cracking: Optimized the equipment ejector motion control logic, combined with flexible buffering process parameters adapted to blue film and ultra-thin chip material characteristics, reducing the instantaneous ejection impact force and minimizing film damage and chip damage.

For unstable chip recognition and recognition failures: Upgraded the vision imaging suite and recognition logic, enhancing the contour capture capability for small chips, improving chip pickup positioning stability, and reducing the frequency of recognition anomalies.

For adhesive pullback and insufficient fillet height: Optimized the entire dispensing control process, adjusted dispense and break-off process parameters, improved adhesive retraction behavior, and ensured uniform and consistent sidewall fillet height during mass production.

Project Feedback

After the optimized solution was put into stable operation on the customer's production line, overall yield improved from less than 92% to 99.8%, reliably supporting the customer's mass production delivery of automotive LiDAR emitter modules.

Customer feedback: "After optimization, the dispensing requirements were met, and it also helped us solve the blue film ejector cracking issue."

Equipment

VCSEL Array Die Bonding

Process Challenges

Solution

Project Feedback

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