Magnetic domain device modular assembly

Plural groups of one or more magnetic domain devices each are mounted in an array on the circuitized surface of a common substrate. A rectangular pattern of slots is provided in the substrate around each group. Each group is encompassed through the slots by the turns of the inner and outer orthogonal solenoids of its own exlusive rotational magnetic field drive system and permanent magnet bias field closed structure. Each device has a pattern of I/O pads located on its undersurface which are bonded to a corresponding pattern of terminal pads which are part of the circuitized surface of the substrate. The interconnecting signal lines to the terminal pads of the substrate pass through one or more of the four intersection corners formed between the slots of the rectangular pattern. Preferably, the substrate also accommodates integrated circuit modules and/or other components mounted thereon which are associated with the drive, sense and other support circuitry for the magnetic domain devices.