Hitachi, Ltd.

Hirofumi Ohta

Toshio Futami

Minoru Hiroshima

Takashi Toyooka

Atsushi Asano

Nobuo Saito

Kazuo Umeyama

A magnetic bubble memory element has a conductor pattern layer including a hair pin shaped conductor loop for generating or dividing magnetic bubbles. A heat sink pattern layer is provided close to the hair pin portion of the conductor loop and may be formed integrally with the loop.

Magnetic bubble memory element with heat sink

A magnetic bubble memory chip is arranged in such a way that the major surface of the chip will not cross perpendicularly with the external bias magnetic field to generate a component of the bias magnetic field which is parallel to the major surface. This component is added to the rotating magnetic field within the chip major surface and the intensity of a resultant rotating magnetic field is shifted to the start/stop direction of this rotating magnetic field. Of the basic elements incorporated in the chip, the basic elements which operate stably in a comparatively intense rotating field is operated in synchronism with the phase of the start/stop direction of the rotating magnetic field in order to ensure stable operation of all the basic elements under the decreased intensity of the external rotating magnetic field.

Magnetic bubble memory device

Around the magnetic bubble memory chip placed within a recess formed at approximate center of the insulating substrate are arranged a plurality of rod-like members of soft ferromagnetic material to be on substantially the same plane as the major surface of the chip. The intensity of the rotating magnetic field generated by the coils wound around the outer periphery of the insulating substrate encircling the chip is amplified by the plurality of rod-like members.

Magnetic bubble memory devices

In a magnetic bubble memory device, positive signal lines interconnecting a magnetic bubble memory chip located at substantially the center of an insulating substrate and lead pins at the end of the substrate are surrounded by a plurality of grounded conductors for shielding the positive signal lines so as to decrease noise induced therein by a voltage drop across coils for producing the rotating magnetic field.

A third conductor is added to a pair of first and second parallel conductors transmitting signals, a part of which conductors are located in an alternating magnetic field. The three conductors are so arranged that the first and third conductors are symmetrical with respect to the center line of the second conductor, and the first and third conductors are interconnected at both extremities thereof.

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Mobara, Japan

Hirofumi Ohta