JPS6059667B2 - magnetic bubble device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to magnetic bubble devices, and more particularly to improvements in magnetic bubble chips.

BACKGROUND OF THE INVENTION Supported by remarkable developments in electronic technology, including semiconductor integrated circuit technology, electronic computers are rapidly becoming smaller and faster.

Furthermore, the reliability has been significantly improved by making the circuit elements solid-state. Furthermore, as the use of electronic computers progresses, the storage capacity of storage devices continues to increase year by year, and there is a strong desire to reduce the unit cost and access time required for storage. In order to reliably store and retain large amounts of information, a highly reliable non-volatile large-capacity memory device is required, but this is impossible to achieve with volatile semiconductor memory, and However, magnetic tape devices, magnetic disk devices, and the like have a fatal flaw in that they have moving parts, and it is difficult to say that these are memory devices that meet needs in terms of reliability.

Magnetic bubbles were invented in view of the above technical background.

When a bias magnetic field of an appropriate magnitude is applied perpendicularly to the surface of a magnetic thin plate such as garnet or orthoferrite having uniaxial magnetic anisotropy, a cylindrical magnetic domain, a so-called magnetic bubble, is generated.

Magnetic bubble utilization devices that use magnetic bubbles to store information, perform logical operations, etc. must be nonvolatile.

Must be an all-solid-state device. Capable of increasing capacity. Due to its relatively high speed, its practical application is rapidly progressing in fields that take advantage of these characteristics. This magnetic bubble utilization device requires various functions such as generating, transferring, dividing, enlarging, detecting, and erasing magnetic bubbles.

Furthermore, a bias magnetic field application means for stably existing magnetic bubbles within the magnetic thin plate, and a rotating magnetic field application for moving the magnetic bubbles within the magnetic thin plate to the base of the magnetic material pattern formed on the magnetic thin plate. Requires means. FIG. 1 shows a typical configuration example of a magnetic bubble chip used in a magnetic bubble utilization device.

The illustrated configuration is a so-called major minor loop configuration, and in the figure, 1 is a major loop, 2 is a minor loop, 3 is a detector, 4 is a generator, 5 is a replicator, 6 is an annihilator, 7 indicates a transfer gate.

In the figure, the solid line represents a magnetic bubble transfer path formed by a permalloy pattern formed on a magnetic thin plate, and the broken line represents a conductive pattern made of gold or the like also formed on the thin plate. The operation is performed as follows. First, in accordance with the information to be written, a current is supplied within the loop of the conductive pattern constituting the generator 4 in a direction that effectively weakens the bias magnetic field, thereby generating a magnetic bubble within the loop.

The generated magnetic bubbles are transferred over the major loop 1 by a driving magnetic field rotating in the in-plane direction of the magnetic thin plate, and are aligned by one piece of information (for example, one word) at opposing positions in each minor loop 2. At this time, a current is supplied to the conductor pattern constituting the transfer gate 7 to send the magnetic bubble group on the major loop 1 into each minor loop 2. The magnetic bubbles sent into each minor loop 2 begin to circulate within the minor loop 2 due to the drive magnetic field, and storage of information is completed. Next, to read information, when the magnetic bubble group in each minor loop 2 to be read reaches a position opposite to the transfer gate 7, the conductor pattern is energized and transferred onto the major loop 1.

The magnetic bubble array transferred onto the major loop is sequentially transferred to the replicator 5 by the driving magnetic field. The replicator 5 divides the incoming magnetic bubble into two, sends one bubble along the permalloy pattern to the detector 3, and sends the other bubble through the major loop 1 to the minor loop again. The detector 3 magnifies the magnetic bubbles that arrive one after another in order to increase the detection efficiency, and reads out, for example, a change in magnetoresistance of the magnetoresistive element due to the arrival of the bubbles as a change in voltage. After reading, if you want to erase the information and write new information, erase the divided magnetic bubbles by the annihilator 6 on the major loop, and write the new information to the generator. Write by 4. FIG. 2 is a configuration diagram of a package that accommodates the magnetic bubble chip shown in FIG. 1.

In the figure, 8 is a magnetic bubble chip, 9 is a chip mounting plane, 10 is an XY coil for generating a driving magnetic field, 11 is a ferrite yoke, 12 is a thin plate magnet for applying a bias magnetic field, and 13 is a shield case. A triangular wave current having a phase shift of 90 degrees as shown in FIG. 3A is applied to each of the XY coils for generating a driving magnetic field to obtain a rectangular rotating magnetic field locus as shown in FIG. 3B. The characteristics of this triangular wave current drive are that the drive circuit is simple, the number of parts is small,
It has various advantages over sinusoidal current driving, such as low driving voltage, low weight, and easy integration. The present invention relates to an improvement of the above-mentioned magnetic bubble device, and in particular to a magnetic bubble chip. The magnetic bubble chip has a generator, transfer path, transfer gate, divider,
It is configured with various functional patterns such as a replicator, stretcher, detector, and eraser.

Each of these functional patterns has a different operating margin, and the total operating margin is determined by the upper and lower limits of each operating margin.

FIG. 4 shows an operating margin characteristic curve of a conventional magnetic bubble device. In the figure, the horizontal axis Hr represents the driving magnetic field, the vertical axis represents the bias magnetic field, and the curve A represents the margin curve of the transfer path.
Also, curve B is the stretcher margin curve, and curve C
respectively indicate the total operating margin width under a certain driving magnetic field. For example, the upper limit of the overall operating margin of the magnetic bubble chip is determined by the operating margin of the stretcher, and the lower limit thereof is determined by the operating margin of the transfer path. Therefore, as is clear from the figure, the overall operating margin is extremely narrow.

The purpose of the present invention is to improve the magnetic bubble chip by
The objective is to expand the overall operating margin of a magnetic bubble device and realize a stable magnetic bubble device.

An object of the present invention is to provide a magnetic bubble chip comprising at least a generator for generating magnetic bubbles, a transfer path for transferring magnetic bubbles, and a detector for detecting magnetic bubbles, and a method for applying a bias magnetic field to the magnetic bubble chip. A conductor for locally changing the bias magnetic field on a surface of the magnetic bubble chip opposite to the surface on which the generator, transfer path, and detector are formed. This can be achieved by using a patterned magnetic bubble device.

The present invention will be explained below with reference to the drawings.

FIG. 5 is a conceptual diagram showing an embodiment of the magnetic bubble device according to the present invention.

In the figure, 14 is a back conductor pattern for locally weakening the bias magnetic field, which is a feature of the present invention. Other numbers are used as they are in Figure 1, but in order to clearly express the detection part, detector 3 in Figure 1 is used as is.
is shown divided into a detection pattern 3'' made of a conductor pattern and a stretcher pattern 3'' made of a permalloy pattern. The operation of the magnetic bubble is no different from the conventional method, so a description thereof will be omitted here.

The difference from FIG. 1 is that the detection section consisting of a detector pattern 3'' and a stretcher pattern 3'' is surrounded by a conductor pattern 14 shown by a dashed line. That is, according to this embodiment, the conductive pattern 14 for weakening the bias magnetic field is arranged on the back surface of the chip so as to surround the detection section on the surface of the magnetic bubble chip. This conductor pattern 1
4, the operating margin curve of the stretcher is shifted up by supplying a current in the direction of weakening the bias magnetic field, which is applied perpendicularly to the surface of the magnetic bubble chip. FIG. 6 shows an enlarged embodiment of the detection section shown in FIG.

Although FIG. 6 shows an embodiment having two sets of detection sections, the principle is the same as the embodiment shown in FIG. In FIG. 6, the back conductor pattern 14 is indicated by a broken line.

The conductor pattern 14 is pattern-formed, for example, by vapor deposition on the back surface of a magnetic bubble crystal for a magnetic bubble thin film (GGG scanning plate). FIG. 7 shows an operating margin characteristic curve of a magnetic bubble chip to which the present invention is applied.

In the figure, the horizontal axis Hr represents the drive magnetic field, and the vertical axis Hb represents the bias magnetic field. The margin curve A of the transfer path is exactly the same as that shown in Figure 4, but the margin curve B'' of the stretcher
is shifted to the high bias side, and as a result, the total operating margin width C'' is clearly expanded compared to the conventional magnetic bubble device shown in FIG. 4. As explained above, according to the present invention, the conventional magnetic bubble device Compared to the above, it is possible to realize a magnetic bubble device with an expanded overall operating margin and stable operation.

In addition, the present invention has a simple structure because there is no need to provide a printed circuit board on which a coil for bias magnetic field adjustment is separately formed, and various functional patterns (generator, transfer filter, etc.) formed on the surface of the bubble chip. This method has the advantage that a conductive pattern is formed on the back surface of only the necessary portions of a stretcher (such as a stretcher), making it possible to easily and reliably adjust the local bias magnetic field.

In the above embodiment, the conductive pattern on the back surface is applied to the detection part, but the present invention is of course not limited to this, and for example, a magnetic bubble which also determines the upper limit of the overall operating margin It is also effective to arrange it in the transfer gate section that changes the transfer path of the sensor, and also in the detector and transfer gate section.

[Brief explanation of the drawing]

Figure 1 is a diagram showing a typical configuration example of a magnetic bubble chip.
Figure 2 is a configuration diagram of a package that accommodates a magnetic bubble chip, Figure 3 is a diagram showing the current waveform for generating a magnetic field for driving a magnetic bubble and its driving magnetic field trajectory, and Figure 4 is an operating margin characteristic of a conventional magnetic bubble device. 5 is a conceptual diagram showing an embodiment of the magnetic bubble device according to the present invention, FIG. 6 is a diagram showing an enlarged embodiment of the detection section shown in FIG. 5, and FIG. FIG. 3 is a diagram showing an operating margin characteristic curve of a magnetic bubble chip to which the present invention is applied. In the figure, 1 is a major loop, 2 is a minor loop, 3 is a detector, 4 is a generator, 5 is a replicator, 6 is an annihilator,
7 is a transfer gate, and 14 is a back conductor pattern.

Claims (1)

[Claims] 1. A magnetic bubble chip comprising at least a generator for generating magnetic bubbles, a transfer path for transferring magnetic bubbles, and a detector for detecting magnetic bubbles; and bias magnetic generation means for applying a bias magnetic field to the magnetic bubble chip. In the magnetic bubble device, a conductive pattern for locally changing the bias magnetic field is formed on the surface of the magnetic bubble chip opposite to the surface on which the generator, transfer path, and detector are formed. A magnetic bubble device characterized by: