A carriage assembly of a hard disk drive is constructed so that the
bonding of flying leads of a long tail suspension circuit board and
bonding terminals of a flexible printed circuit board can be carried out
uniformly and reliably, and the problem of the flying leads breaking when
the flying leads are pulled off the bonding terminals does not occur. The
flexible printed circuit board is attached to a reinforced part by an
adhesive in which spacers with a substantially equal particle diameter
are mixed, and the flying leads and the bonding terminals are bonded
together by ultrasonic bonding by applying ultrasonic vibration in a
state where the flying leads are pressed onto the bonding terminals. In
addition, an insulating film is provided on an opposite surface of the
flying leads to the surface bonded to the bonding terminals, and during
the ultrasonic bonding, ultrasonic vibration is applied in a state where
the flying leads are pressed via the insulating film onto the bonding
terminals.