US Patent 10984708 Manufacture LED displays using temporary carriers

To manufacture a display using light emitting diodes (LEDs), the LEDs are transferred from fabrication substrates where they are fabricated to a target substrate (e.g., a backplane) that forms part of a display. The LEDs are transferred in three stages: first from fabrication substrates to hard handles, subsequently from the hard handles to a carrier substrate, and last from the carrier substrate to the target substrate. The LEDs are placed onto the carrier substrate to form pixel arrangements. One or more pick-up tools are used to transfer the LEDs. Switchable adhesives are used to facilitate the transfer of the LEDs from the fabrication substrates to the target substrate.