Researchers from the University of Waterloo in Canada developed a new transfer and bonding method to deposit a flexible microLED array on plastic substrates.
The technique, referred to as a "paste-and-cut", starts with temporarily bonding the LEDs on a process/handle wafer onto a glass substrate (the paste step). The LEDs are then released (cut) to the flexible substrate. This approach allows the LED to be optimized and then combined with other materials.
The researchers explain that the use of a metal bonding layer enhances the electrical and thermal conductivity of the diode structure on the flexible substrate. Plastic substrates problematic because of the electrically and thermally insulating nature of the plastic, and this simple bonding layer design approach overcomes these limitations.