Characteristics of particle deposition on disk in disk drives

The characteristics of particle deposition on disk surfaces in hard disk drives (HDDs) was studied. The density of tracer particles deposited on the disks was measured to determine the deposition profile. The circumferentially averaged deposition density increases monotonically with radius. The number of deposited particles on the two outermost disk surfaces is more than twice that on other disk surfaces in the HDD. An obstruction to the flow unequally enhances the particle deposition on the disk: 15 percent to the two outermost surfaces, and 55 percent to the other surfaces. These features can be explained satisfactorily by the airflow characteristics in the HDD.