InFO_AiP technology, with low loss chip-to-antenna interconnect and wideband slot-coupled patch antenna, is proposed for low power, high performance, and compact 5G millimeter wave (mmWave) system integration. The low loss chip-to-antenna interconnect is related to low metal surface roughness of redistribution layer (RDL) and smooth interconnect transition between chip and package in InFO technology. The InFO RDL with low metal roughness results in transmission loss of 0.3 dB/mm which is lower than the loss of Cu trace on substrate, and the smooth interconnect transition with low discontinuity structure reduces the interconnect loss, by 0.78 dB at 60 GHz. A wideband slot-coupled patch antenna is designed successfully with 22.8% FBW (56.6-71.2GHz) and over antenna gain of 3 dBi in the operating band. To verify the technology performance, an InFO_AiP sample at 60 GHz is first designed, fabricated, and measured. The measurement result has a good agreement with the simulation and shows S11 ? -10 dB bandwidth of 55-65 GHz. As a result, InFO_AiP is a leading technology for 5G mmWave system application from power and performance considerations.