US Patent 10177196 Redundancy in inorganic light emitting diode displays

Methods and apparatus for use in the manufacture of a display device including pixels. Each pixel includes a plurality of sub-pixels, each sub-pixel configured to provide light of a given wavelength. The method may include: performing, using a pick up tool (PUT), a first placement cycle comprising picking up first light emitting diode (LED) dies, and placing a first LED die on a substrate of the display device at a location corresponding to a sub-pixel the display device. The method further includes performing one or more subsequent placement cycles comprising picking up a second LED die, and placing the second LED die on the substrate of the display device at a second location corresponding to the sub-pixel of the display device. Multiple first and second LED dies may be picked and placed during each placement cycle to populate each pixel of the display device to provide redundancy of LED dies at each sub-pixel.