Design,fabrication and characterizations of GaN-based blue micro light emitting diode (LED) arrays are reported.The GaN micro-LED array consists of 320 × 256 pixels with a pitch size of 30 μm.Each pixel is 25 × 25 μm2 in size,which is designed for backside emission and high density flip-chip packaging.The selected LED pixels being tested exhibit good uniformity in terms of tu-on voltage and reverse leakage current.The efficiency droop behavior and reliability behavior under high forward current stress are also studied.The micro-LED pixel shows improved reliability,which is likely caused by enhanced heat dissipation.