Disclosed is a mobile Integrated Battery Powered Hard Disk Drive (IBP-HDD) equipped with USB OTG capabilities for direct connection to other USB devices, such as cell phones, PDAs, MP3 players, GPS, digital camcorders, digital cameras and other devices. These drives come in all form factors and combine high storage capacity and performance with low power consumption and portable operation. One component of the integrated drives is the base upon which all components and assemblies of the HDD have been mounted to produce a Drive-On-A-Substrate. A cover mounts to the base and separates each component and assembly into isolated compartments that can be evacuated of air and refilled with inert gases for improved performance and reliability. A first embodiment of the invention involves a method to manufacture a base. A second embodiment of the invention involves a method to manufacture an integrated battery powered hard disk drive portion on a base. A third embodiment involves a method to assemble an integrated battery powered hard disk drive.