Patent ID: 8035915

Claim:
A magnetic disk drive comprising: a housing having a first rectangular surface and first and second columnar protrusions formed on the first rectangular surface; and a rectangular circuit board having two sets of parallel edges and a first circuit which includes a hard disk controller, an MPU, and a read/write channel, and a second circuit housed within a package and which includes a motor drive unit, and provided with a first columnar aperture and a second columnar aperture; wherein the center of the first protrusion lies on a short side center line parallel to the short sides of the first surface or at a position deviated from the short side center line, wherein the center of the second protrusion lies on a long side center line parallel to the long sides of the first surface or at a position deviated from the long side center line on the side opposite to the side where the center of the first protrusion is positioned, wherein the circuit board is fixed to the first surface of the housing in a mutually fitted state of the first aperture and the first protrusion and in a mutually fitted state of the second aperture and the second protrusion, wherein the center of the first circuit lies on the circuit board on the side where the center of the second protrusion is positioned with respect to the short side center line parallel to the short sides of the first surface and on the side opposite to the side where the center of the second protrusion is positioned with respect to the long side center line parallel to the long sides of the first surface, and wherein the center of the second circuit lies on the circuit board at a position between the center of the first protrusion and the center of the second protrusion in the longitudinal direction of the first surface and on the side where the center of the second protrusion is positioned with respect to the long side center line parallel to the long sides of the first surface, wherein the second circuit is disposed on the circuit board in such a manner that an extension line in a direction of a straight edge of the package intersects one of the edges of the circuit board obliquely.