Disk drive having a base with a protruding peripheral metal flange that is folded over a top cover to enclose helium

A method to manufacture a disk drive comprising:

• providing a disk drive base having a bottom portion and four side walls that define a cavity therebetween;
• attaching and hermetically sealing a metal flange to the disk drive base with the metal flange positioned to protrude from all four side walls of the disk drive base;
• rotably mounting at least one disk to the disk drive base, the at least one disk defining a disk axis of rotation normal to a disk major surface;
• and
• continuously adhering a top seal to the largest exposed surface of the metal flange along an entire length of all four side walls, with the top seal spanning the cavity;
• folding the metal flange over the top seal along all four side walls, so that a folded portion of the metal flange concludes substantially parallel with the top seal;
• introducing helium into the cavity.