Then iron the printed layout at minimum heat until the ink sticks to the PCB. It may take more than an hour to finish. Remove the transparent paper afterwards. 6) After that, submerge the PCB with Ferric Chloride Liquid until the expose copper is totally dissolved. Carefully make sure that the ink does not also dissolve so it can protect the wa
nted copper underneath. 10)Drill some hole on the remote control car to put the PCB stands. This will prevent the circuit from moving. Screw the circuit onto the remote control car.