Thiophene-containing photo acid generators having either of the following general formulas: . A file is broken into a plurality of pieces. The tubes of each boiler form at least one water wall. Multiple serpentine springs serve as the flexible hinges that link the movable structure to the stationary support structure. Otherwise, sending the new IO request to the disk drive is deferred until the sweep direction is set to a reverse direction. The motor control board is fixed to the motor via the coupling unit such that the motor control board is disposed below the motor and above the trigger switch.