JPS6346918B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic memory element that utilizes magnetic bubbles.

The method of moving magnetic bubbles uses a soft magnetic film such as a permalloy pattern, and a magnetic field drive method that applies a rotating magnetic field from the outside, and a method that uses a magnetic field drive method that applies a rotating magnetic field from the outside, and a method that uses a magnetic field drive method that applies a rotating magnetic field from the outside.
There is a current drive method that uses the resulting magnetic field to move magnetic bubbles.

With the current drive method, it is relatively easier to obtain a high-speed memory element than with the magnetic field drive method, and various drive methods have been proposed. Among these methods, the most practical method is to make holes in a two-layer conductive sheet and use the leakage magnetic field from the holes to move magnetic bubbles.
For more information, see Bell System Technical Journal, Volume 58, vol.
Shown in 1453-1540 Tribute (1979).

A disadvantage of the magnetic bubble device using a conductive sheet is that since it is necessary to pass current through a wide conductive sheet, the total current becomes large, and the heat generation of the magnetic bubble memory chip due to the current increases.

One way to reduce drive power is to split the information storage loop and drive only the parts that are needed.

FIG. 1 shows a portion of a divided storage loop. A row of holes 13 in the conductor sheets 11 and 12,
14 are each opened to form a first storage loop. Currents 15, 16 allow the magnetic bubble to move along the first storage loop. There are conductor sheets 11, 12 and separate conductor sheets 17, 18, each having a row of holes 19, 20, forming a second storage loop. Currents 21, 22 allow the magnetic bubble to move along the second storage loop.

In order to effectively write and read information, it is necessary that the information in the first and second storage loops, that is, the magnetic bubbles, can be exchanged. More specifically, the magnetic bubbles located at the positions of the notch patterns 23 and 25 provided at the ends of the conductive sheets 12 and 18 are connected to the conductive sheets 17 and 18, respectively.
Notch pattern 26, 2 provided at the end of 11
Must be able to transfer to position 4. This kind of functional unit operation is commonly called a swap.

To perform this operation, a third control conductor is usually used, and the magnetic field generated by the third control conductor causes the magnetic bubbles to be transferred.

Conventionally, it has been known that the third control conductor may have a hairpin shape. FIG. 2 shows a swap function designed according to the conventional scheme. By passing current through the control conductors shown at 27 and 28, the magnetic bubble 30 at position 25 is moved to position 24, and the magnetic bubble 29 at position 23 is moved.
can be moved to position 26. In such a system, the width of the control conductor generally needs to be smaller than the size of the hole in the conductor sheet. The size of the magnetic bubble and the size of the hole are approximately the same, so problems arise in terms of processing technology when trying to construct a high-density memory device using minute magnetic bubbles. In the magnetic field drive system, a similar problem can occur with conductors for controlling functional parts such as swaps.

It is an object of the invention to eliminate the dimensional problems of the control conductors of the prior art.

According to the present invention, by using a control conductor having a hole pattern in the functional part, it is possible to construct a memory chip with at least the same dimensional accuracy as other patterns.

Next, the present invention will be explained in detail using examples.
FIG. 3 shows an embodiment of a control conductor pattern in a functional part according to the invention. Hole pattern 3 on control conductor 31
2 and a cutout pattern 33. By using the magnetic field distribution generated near the hole pattern 32 and the notch 33, it is possible to perform the same operation as a thin hairpin pattern with a rough precision pattern. The movement of the magnetic bubble in the swap section using the control conductor shown in FIG. 3 will be explained in detail with reference to FIGS. 4-8. In FIG. 4, arrow 41 indicates the direction of movement of the magnetic bubble in the first storage loop. Arrow 42 indicates the direction of movement of the magnetic bubble in the second storage loop. Consider exchanging the magnetic bubble 43 at position 23 with the magnetic bubble 44 at position 25. First, as shown in FIG. 5, when a current Ic, 50 is passed through the control conductor 31, the magnetic field caused by the current moves the magnetic bubble 43 from the position 23 to the position 51, and the magnetic bubble 44 from the position 25 to the position 52. The other magnetic bubbles in the first and second storage loops remain stationary. Next, as shown in Fig. 6, the control conductor 3
When a current Ic, 53 in the opposite direction is applied to 1, a magnetic bubble 4
3 is at position 51 to 61, magnetic bubble 44 is at position 5
Move from 2 to 62 position. Next, as shown in FIG. 7, currents I ₁ and 7 are applied to the conductor sheets 11 and 17, respectively.
1, I ₁ ', 72, the magnetic bubble 43 moves from 61 to 26, and the magnetic bubble 44 moves from 62 to 24.
move to the position. In this way, the position 25 of the magnetic bubble 44 is moved from the position 23 to the position 26 of the magnetic bubble 43.
The transition from to 24 is completed, and the swap operation is completed. Thereafter, as shown in _{FIG .}
2, and then conductor sheets 11, 12, 17, 1
When currents I ₁ , I ₂ , I ₁ ′, and I ₂ ′ are sequentially applied to 8, the magnetic bubble will eventually move within the first and second memory loops.

If it is desired to replace the magnetic bubble array, the operations shown in FIGS. 5 to 8 may be repeated. Thus, it has been shown that the swap operation can be performed using the simple hole pattern shown in FIG. 3 and the control conductor having notches.

Although the above embodiment shows a swapping operation of magnetic bubbles between memory loops, it is of course possible to simply swap magnetic bubbles between transfer lines, or between a memory loop and a transfer line. be. Furthermore, it is of course possible to design a control conductor having a hole pattern etc. in accordance with the spirit of the present invention for a transfer operation of one magnetic bubble between storage loops rather than a swap operation, that is, a transfer operation. It is.

In addition, the hole pattern is not limited to an elliptical shape as in the embodiment, but a rectangular shape or the like may be used as well. Furthermore, it can be achieved not only by a combination of a hole pattern and a notch pattern, but also by a hole pattern alone.
Of course, the pattern arrangement can also be modified depending on the purpose. In addition, although this example shows the control conductor in the swap part of a current-driven magnetic bubble device, the control conductor according to the present invention can also be used in a magnetic bubble device using a permalloy pattern or a magnetic bubble device using an ion implantation pattern. Needless to say.

According to the present invention, it is possible to relatively increase the minimum dimension of the control conductor pattern of a magnetic bubble device, and a high-density magnetic bubble device can be realized.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a part of the memory loop of a current-driven magnetic bubble device, with 11, 12,
17, 18 are drive conductor sheets, 13, 14, 1
9, 20 are hole patterns, 15, 16, 21, 22
is the drive current to the conductor sheet, 23, 24, 25,
26 represents a notch pattern. FIG. 2 is a plan view showing the swap gate section according to the conventional design method, in which 27 and 28 are control conductors;
9 and 30 represent magnetic bubbles. FIG. 3 is a plan view showing a control conductor pattern in one embodiment of the present invention, in which 31 represents a control conductor, 32 represents a hole pattern, and 33 represents a notch pattern. 4 to 8 are plan views sequentially showing the swapping operation of an embodiment of the present invention, 41 and 42 are moving directions of magnetic bubbles, 43 and 44 are magnetic bubbles, 50,
53 is the current to the control conductor, 71, 72, 81, 8
2 is the current to the drive conductor sheet, 51, 52, 6
1, 62 represents the position of the magnetic bubble.

Claims (1)

[Claims] 1. It has a magnetic film capable of holding magnetic bubbles, a magnetic means for making the magnetic bubbles stably exist, and a magnetic means for moving the magnetic bubbles, and the moving means includes one moving path and another. In the magnetic storage device, the magnetic storage device includes means for transferring a magnetic bubble between the movement paths by passing a current through the conductor pattern, the conductor pattern being disposed between the conductor pattern and the movement path, the conductor pattern being strip-shaped; A magnetic bubble element characterized in that the conductor pattern is provided with patterns such as holes and notches so that when a current is passed through the conductor pattern, a magnetic field capable of trapping magnetic bubbles is generated at a predetermined position between the movement paths.