Base unit and disk drive apparatus

A base unit for use in a disk drive apparatus in which a gas with a density lower than that of air is sealed in a housing space defined by a base member and a cover fixed to each other, the base unit comprising:

• the base member that supports a motor rotatable about a central axis extending in a vertical direction;
• and
• a connector electrically connected to a wire in the housing space;
• wherein
• the base member includes:
• a recessed portion that extends in radial directions and is recessed upward from a lower surface of the base member, the radial directions being perpendicular or substantially perpendicular to the vertical direction;
• and
• a hole portion that passes through the recessed portion in the vertical direction;
• the recessed portion includes a recessed portion loop-shaped surface defining a loop-shaped surface perpendicular or substantially perpendicular to the vertical direction;
• the connector is on a lower side of the recessed portion to cover the hole portion;
• an adhesive is between the connector and the recessed portion;
• and
• a minimum value of a gap distance between an outer end of the connector and an inner end of the recessed portion in a radial direction in which the outer end of the connector and the inner end of the recessed portion are opposed to each other with the adhesive therebetween is greater than a minimum value of a gap distance between an upper surface of the connector and the recessed portion loop-shaped surface in the vertical direction, in which the upper surface of the connector and the recessed portion loop-shaped surface are opposed to each other with the adhesive therebetween;
• wherein
• the recessed portion loop-shaped surface or each of the outer end of the connector and the inner end of the recessed portion have a degree of surface roughness greater than a degree of surface roughness of the upper surface of the connector.