HEAD STACK ASSEMBLY AND ITS MANUFACTURING METHOD AND MAGNETIC DISK DEVICE HAVING THE HEAD STACK ASSEMBLY

PROBLEM TO BE SOLVED: To provide the manufacturing method of a head stack assembly which can effectively suppress deformation of an arm and to provide a magnetic disk device having the head stack assembly. SOLUTION: The manufacturing method is for the head stack assembly which has a suspension 130 that supports a head, an arm 144 that drives the head and base plates 150 that mount the suspension 130 onto the arm 144. The base plates 150 are fastened, by caulking, to the arm 144 by inserting the base plates 150 having bosses that have openings into the through-hole of the arm 144 and by passing a processing member, whose size is larger than the openings, through the openings of the bosses in one direction within the through-hole. Let the surface, which makes the thickness of the arm 144 one half, be the neutral surface. Then, the caulking position, which is the middle position between a first position located at the uppermost stream side and a second position located at the most downstream side, is set within the range of ±10% of the thickness of the arm 144 from the neutral surface. COPYRIGHT: (C)2007,JPO&INPIT