A head actuator assembly comprises a plate-like suspension having a distal
end portion mounting with a magnetic head, and a trace having a relay FPC
attached to the suspension through a lining plate. A head IC is mounted
on the relay FPC and positioned near the magnetic head. In an area which
faces the head IC, insulation layers of the FPC are removed, and an
opening is formed in the lining plate and suspension. A wiring pattern of
the relay FPC is exposed through this opening.