Abstract: An improved coil construction for the voice coil motor of a transducer positioning system of a magnetic disk drive results in increased coil strength while eliminating the tendency of volatile materials associated with either the assembly process or the coil insulation to be entrapped between turns. Insulated aluminum ribbon wire having a rectangular cross-section is edge wound on a mandrel with adjacent turns being bonded together and then subjected to a curing process. By subjecting the ribbon wire to a knurling process prior to winding, the flat surfaces of the ribbon wire are provided with a plurality of knurl prints on each side which extend between opposite edges of the wire in a direction transverse to the lengthwise dimension of the ribbon wire. After winding, the knurl prints serve as interturn vents to prevent entrapment of any volatile materials generated during the curing process. The construction substantially doubles the tensile strength of the coil.