New drive system and packaging method for magnetic bubble memory

We developed a new drive system and packaging method for magnetic bubble memory. Coils wound around a picture frame core and surrounded by a conductive shield box make the rotational magnetic drive field uniform and exist only in very limited space. A flexible printed circuit is used to reduce the space for I/O signal wiring. Using these with a 4-Mbit, 15.4mm × 15.6mm chip, we demonstrated a significantly miniaturized module with a size of 24mm × 24mm × 6mm, approximately one fourth that of the conventional one. This will extend the application range of the magnetic bubble memory.