Fan-Out Panel-Level Packaging of Mini-LED RGB Display

In this study, the feasibility of mini-light-emitting diode (LED) RGB display fabricated by a chip-first fan-out panel-level packaging is investigated. Emphasis is placed on the design, materials, process, fabrication, and reliability of the mini-LED RGB display package on a printed circuit board (PCB). The mini-LEDs under consideration and their sizes are red ( 125 ×250 ×100 μm), green ( 130 ×270 ×100 μm), and blue ( 130 ×270 ×100 μm). The spacing among the RGB mini-LEDs is 80 μm, the pixel-to-pixel spacing is also ~ 80 μm, and the pixel pitch is 625 μm. The temporary glass panel for making the redistribution layers (RDLs) of the package is 515 ×510 ×1.1 mm in size. To increase the SMT assembly yield on the PCB, the mini-LEDs are grouped into 4( 2 ×2 pixels)-in-one surface mount device (SMD), that is, a total of 12 R, B, and G mini-LEDs. A PCB ( 132 mm ×77 mm) is designed and fabricated for the drop test of the mini-LED package. Thermal cycling of the mini-LED SMD PCB assembly is also performed by a nonlinear temperature- and time-dependent finite-element simulation.