The head stack assembly of a hard disk drive includes a bobbin, and a printed circuit board attached to the bobbin. The bobbin forms an end of the head stack assembly that is rotatable about an axis of a shaft. The printed circuit board has a flat conductive pattern of a plurality of traces through which current is supplied. The conductive pattern constitutes the voice coil motor of the hard disk drive. The hard disk drive has magnets disposed above and below the bobbin, respectively, to generate a magnetic field across the conductive pattern such that an electromotive force that rotates the HSA is produced when current flows through the conductive pattern. The flat conductive pattern allows the voice coil motor to be relatively thin while the magnets need to encompass only a small region making the hard disk drive compact and lightweight.