Patent ID: 8031439

Claim:
A head stack assembly (HSA) of a hard disk drive, the assembly comprising: a swing arm; a read/write head supported by the swing arm at one end of the HSA; a bobbin integral with the swing arm and constituting the other end of the HSA, the swing arm and the bobbin being disposed on opposite sides of an axis of rotation of the HSA; and a printed circuit board attached to and extending along the bobbin, the printed circuit board including a substrate, and a conductive pattern supported by the substrate, wherein the conductive pattern comprises a series of conductive traces that extend parallel to one another and approximately radially with respect to the axis of rotation of the HSA, the conductive traces are electrically connected to one another in parallel, and the printed circuit board is U-shaped and has a wide portion extending approximately radially with respect to the axis of rotation of the HSA, a narrow portion spaced from the wide portion and also extending approximately radially with respect to the axis of rotation of the HSA, and a connecting portion that connects the wide portion to the narrow portion and has approximately the shape of an arc centered about the axis of rotation of the HSA, the series of conductive traces extending along the wide portion of the flexible printed circuit board, and the series of conductive traces having an overall width that is less than that of the narrow portion as measured in a direction concentric with the axis of rotation of the HSA.