Abstract: A laminated case for a magnetic disk having a pair of outer laminae and a spacer lamina sandwiched therebetween. The spacer lamina adds rigidity to the laminated case and controls the height of a cavity in which the magnetic disk is located. A liner for wiping the disk is attached to each of the outer laminae. The liner has a free hanging section which provides the wiping action. The three laminae are ultrasonically welded together by a method which employs a fixture and an ultrasonic welding horn. The method permits the magnetic disk to be tested and discarded without sacrificing the laminated case.

Abstract: A micro disk for data storage has a media portion of flat circular shape with a central opening therein. A hub portion has a pilot protrusion that interfits with the central opening to mechanically lock the media portion against rotation on the hub portion. The media portion is supported adjacent the central opening to maximize the unsupported radial dimension from the media support to the inner recording track. Thus good flexiblity at the inner recording track of the media portion compensates for variations of the spindle-to-head dimension in disk drive systems and makes the disk suitable for double sided, high density, data storage applications. A modified hub portion is centered on a drive spindle by a leaf spring within the hub portion.