BASE PLATE, BASE UNIT, MOTOR, DISK DRIVE APPARATUS AND METHOD OF MANUFACTURING THE BASE PLATE

摘要

A base plate of a disk drive apparatus includes a motor base disposed around a central axis and a base body portion extending radially outward of the motor base. The motor base is made of a metallic material of a first type. The base body portion is made of a metallic material of a second type. The base body portion is a casting product in which the motor base is an insert component. An upper protruding portion and a lower protruding portion are defined in one of an outer end portion of a bottom plate portion of the motor base and an inner end portion of the base body portion.