I’m at the PlayNitride booth at DisplayWeek 2024, where they showcased several microLED display technologies built on three types of backplanes: PCB, TFT LTPS on glass, and silicon. Here’s a breakdown of their demos and developments.
PCB-Based Cube Display
- Design: A cube with microLED displays on five sides.
- Structure:
- Composed of multiple microLED packages.
- Each package: 1.1 × 1.1 mm, containing a 4 × 4 RGB microLED array.
- MicroLED size: 15 × 30 microns, flip-chip configuration.
- Manufacturing: Compatible with SMT processes, similar to current LED video wall assembly.
- Brightness:
- Current demo: 3,000 nits.
- Can reach 30,000 nits due to passive-matrix design, which allows higher driving currents.
- Pixel pitch: ~0.33 mm (76 PPI), with plans to reduce further.
- Resolution per display: 240 × 240 pixels.
- Driver: Requires a separate driver chip, similar to standard video wall modules.
Transparent MicroLED with LCD Blocking Layer
- Configuration:
- Transparent microLED panel bonded with an LCD cell for adjustable opacity.
- Functionality:
- Transmissivity ranges from 1% to 40%.
- Fully blocked mode creates an opaque display for privacy or enhanced contrast.
- Panel specs:
- Size: 9.38 inches.
- Resolution: 960 × 480 pixels.
- Pixel pitch: 0.22 mm (114 PPI).
- Use case: Automotive or retail displays requiring switchable transparency.
CMOS Backplane and Manufacturing Process
PlayNitride highlighted its chip-on-carrier (COC) process:
- Starts with red, green, and blue epi wafers.
- Transfers to COC1, then to COC2 for final pixel pitch.
- Enables creation of small packaged modules for flexible assembly.
AR MicroLED Update
- Display size: 0.49 inches, optimized for AR.
- Resolution: Full HD.
- Color conversion: Quantum dots via photolithography.
- Yield: 99%, a significant achievement.
- Brightness: Increased from 150,000 nits last year to 300,000 nits.
- Color gamut: Specified as 100% NTSC (though this metric is outdated).
Key Takeaways
PlayNitride is advancing microLED technology with:
- High-brightness passive-matrix designs for signage.
- Transparent displays with dynamic opacity control.
- Miniaturized AR panels with exceptional brightness and yield.
- A scalable manufacturing process for future applications.