Glass-Based 4-in-1 High-Voltage Micro-LED Package for High-Brightness Mini-LED Backlight Applications

Area of Science:

• Optoelectronics
• Semiconductor Devices
• Materials Science

Background:

• MicroLED technology is advancing for display and communication applications.
• High-voltage driving circuits for MicroLEDs often require complex converters.
• Transparent substrates offer advantages in light extraction and thermal management.

Purpose of the Study:

• To demonstrate a novel four-in-one (4-in-series) MicroLED-in-Package (MiP4) architecture.
• To evaluate the performance of the MiP4 device for high-voltage applications.
• To assess the potential of this architecture for next-generation displays and optical systems.

Main Methods:

• Integration of four sub-85 µm blue micro-LED dies on a transparent glass substrate using redistribution-layer (RDL) interconnection.
• Electrical and optical characterization of dual-, triple-, and quad-chip devices.
• Pulse-driven measurements to assess thermal stability and spectral shift.

Main Results:

• The MiP4 device operates natively at 16 V, simplifying driving circuits.
• Achieved 1.8× higher optical power and 64 lm/mm² luminous flux density compared to a commercial LED.
• Demonstrated excellent thermal stability and minimal spectral shift (<1 nm) under pulsed operation.

Conclusions:

• The 4-in-1 high-voltage glass-based µ-LED package is a scalable and manufacturable solution.
• This architecture enables ultra-thin, high-brightness Mini-LED backlights.
• The MiP4 technology is suitable for advanced optical communication systems.