In WLP, the ICs are fabricated and tested on the wafer. A redistribution layer (RDL) is then added to reroute the input/output (I/O) pads to desired locations on the die. Following this, solder bumps or other interconnects are formed on the RDL to connect the die to the package or directly to the Printed Circuit Board (PCB). The wafer is then diced into individual chips, each already packaged and ready for assembly.
