Magnetic disk drive having circuit board apertures fitted with protrusions to achieve efficient layout of circuit elements

摘要

Embodiments of the invention provide an efficient layout of circuit elements on a circuit board. A hard disk drive (HDD) according to one embodiment of the present invention is provided with a circuit board. The circuit board has an IC of HDC, MPU, and R/W channel, an IC of MDU, an SPM aperture, and a carriage bearing aperture. The IC is provided on the circuit board on the side where the center of a carriage bearing protrusion is positioned with respect to a central line AB parallel to the short sides of the surface of the housing and on the side opposite to the side where the center of the carriage bearing protrusion is positioned with respect to a central line CD parallel to the long sides of the surface of the housing. The IC of MDU is provided on the circuit board on the side where the center of the carriage bearing protrusion is positioned with respect to the central line CD and at a position between the center of an SPM protrusion and the center of the carriage bearing protrusion in the longitudinal direction of the surface of the housing.