Methods, Materials, and Apparatus for Wavelength Converter Printing for Micro-Pixelated LEDs

Applications

These methods, materials, and apparatus for printing micro-pixelated LEDs aim to address the need for increased brightness, longer lifetimes, and higher resolution in smaller ultrathin device screens. Utilizing the full RGB spectrum for a micro-pixelated LED display, this technology could be of significant use for small screens in AR, VR (Near to Eye), and wearable devices.

Problem Addressed

Current display technologies for large screens, such as Liquid Crystal Displays (LCDs) and Organ Light Emitting Diodes (OLEDs), will not be able to address the need for higher brightness and resolution in future small screen devices given their significant waste of generated light and shorter lifetimes. Further microLEDs are currently limited by monolithic single-color micro-emitters.  Also, there are challenges with printing quantum dot converters to functionalize LEDs across the RGB spectrum. 

Technology

The ink composition for this stereo-lithographic method of printing contains a photo-curable polymer with dispersible light converting sub-micron particles capable of crosslinking by photoactivation. This UV photoactivation forms a uniform and solid quantum dot composite film. The film takes advantage of the numerous benefits of monochrome pixelated LEDs as a substrate and adds the capacity to convert blue pixels to red and green pixels using the printed phosphor layer of quantum dot converters.

The apparatus uses projection micro-stereolithography, allowing for increased control over the dose of UV exposure, through the projection time and power. This optimally cures the polymer and quantum dot composite, resulting in a wavelength converting film.

Advantages

  • Printing quantum dot ink with precision in size, shape, and pitch at high throughput
  • Ink formulation capable of complete blue radiation conversion
  • MicroLED surface modification to achieve high QD ink adhesion and shape accuracy
  • Ability to manufacture wavelength converters onto micro-pixelated LEDs

Intellectual Property

IP Type: Pending PCT Application

IP Title: Methods, apparatuses, and materials for producing micro-pixilated LEDs using additive manufacturing