A circuit board for a brushless DC motor whose rotation is controlled based on data stored on a rewritable non-volatile memory of a micro-computer mounted on the circuit board includes a substrate defined by a plurality of a circuit areas and a non-circuit area. The circuit areas and the non-circuit area are connected by a plurality of conductive patterns. The micro-computer having the rewritable non-volatile memory is mounted on each of the circuit areas. The rewritable non-volatile memory is connected to writing terminals arranged on the non-circuit area by the conductive patterns. By connecting a program writer to the writing terminals and activating the program writer, data are written to the rewritable non-volatile memory of each of the circuit areas. After writing data, the circuit areas are detached from the substrate, and a plurality of circuit boards are manufactured.