JPS6322382B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a magnetic bubble memory device used as a storage device for an electronic computing device.

Conventional technology and problems Conventionally, the propagation path of a magnetic bubble memory element has a first
A propagation path 1 formed by a permalloy thin film as shown in FIGS. a and b, and a propagation path 2 formed by ion implantation as shown in FIGS. 2 a and b are known. All of them are formed by applying photolithography technology. However, the former permalloy propagation path 1 requires a gap g of 2/3 or less of the bubble diameter, so when using microbubbles of about 1 μm, the gap g is 0.7 μm.
The following gap was required, and there were drawbacks that could not be achieved using normal photolithography technology. On the other hand, the latter ion implantation propagation path 2 propagates bubbles through a charged wall that occurs at the boundary between the ion implanted part and the non-ion implanted part, so it does not require a gap and propagates bubbles of 1 μm or less with a minimum dimension of about 1 μm. can be done. However, when the bubble is stopped and held in this ion implantation propagation path, it can be held in the concave portion (hereinafter referred to as the cusp) 4 with an extremely small holding magnetic field (hereinafter referred to as the hold magnetic field), but it is stopped in the convex portion (hereinafter referred to as the tape) 5. In order to hold it, an extremely large holding magnetic field is required. As shown in Fig. 3, even if the hold magnetic field direction 6 is changed by 90 degrees, there is always one or more bubbles 7 that stop at the tape, so the overall size of the hold magnetic field must be extremely large. It was hot. Note that in the permalloy propagation path, it is possible to stop and hold at any position with a small hold magnetic field.

OBJECTS OF THE INVENTION In view of the above-mentioned conventional drawbacks, the present invention provides a magnetic bubble memory element that can form a propagation path for microbubbles using ordinary photolithography technology and can hold bubbles with a small holding magnetic field. The purpose is to

Structure of the Invention According to the present invention, in a magnetic bubble memory element in which a bubble propagation path is formed on the surface of a bubble crystal by ion implantation, the ion-implanted bubble propagation path is such that bubbles are prevented from being formed on the propagation path by a holding magnetic field. This is achieved by providing a magnetic bubble memory element characterized in that a permalloy propagation element is arranged along the ion implantation propagation path near the convex portion where the ion implantation stops.

Examples of the invention Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 4 is a diagram for explaining the magnetic bubble memory element according to the present invention, in which a is a block diagram and b is an explanatory diagram of the operation. In the figure, 10 indicates an ion implantation section, 11 a non-ion implantation section, 12 an ion implantation propagation path, and 13 a permalloy propagation element.

In this embodiment, as shown in the figure, the ion implantation propagation path 12
A chevron-shaped permalloy propagation element 13 is arranged along the vicinity of the tape where the bubble is stopped by the holding magnetic field.

In this embodiment configured in this way, the gap between the permalloy propagation elements 13 is connected to the ion implantation propagation path 1.
Since the cusp 14 of No. 2 takes charge of propagation, the gap g of the permalloy propagation element 13 can be made larger than the bubble diameter. Therefore, it is possible to create a propagation path for microbubbles even with ordinary photolithography technology.

In addition, to stop and hold the bubble, if the hold magnetic field 15 is applied in the direction of the arrow as shown in FIG. Bubbles 16 and 17 are held respectively. The required holding magnetic field at this time is sufficient to stably hold the bubble at the apex of the permalloy propagation element 13, and is less than 1/3 of the size when holding the bubble at the tape of the ion implantation propagation path. .

FIG. 5 is a diagram for explaining another embodiment, in which a shows a diamond type and b shows a non-diamond type. In this figure, the same parts as in FIG. 4 are designated by the same reference numerals.

This embodiment differs from the previous embodiment in that the permalloy propagation elements 13 in both a and b are asymmetric chevrons.

In this embodiment configured as described above, the permalloy propagation element 13 is asymmetrical with respect to the bubble traveling direction indicated by the arrow, so that bubble propagation is further stabilized compared to the previous embodiment.

Effects of the Invention As described above in detail, the magnetic bubble memory element of the present invention includes a permalloy propagation element disposed near the tape of the ion implantation propagation path, and the permalloy propagation element takes charge of bubble propagation in this portion. In the gap part, the ion implantation propagation path is responsible for propagation, and the propagation path for microbubbles can be formed using ordinary photolithography technology, and the bubbles can be held with a small holding magnetic field. The effect is huge.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a propagation path using conventional permalloy, Fig. 2 is a diagram showing a propagation path using conventional ion implantation, Fig. 3 is an explanatory diagram of the bubble stop position in the conventional ion implantation propagation path, and Fig. 4 5 is a diagram for explaining the magnetic bubble memory device according to the present invention.
The figure is a diagram for explaining another embodiment. In the drawings, reference numeral 10 indicates an ion implantation section, 11 indicates a non-ion implantation section, 12 indicates an ion implantation propagation path, and 13 indicates a permalloy propagation element.

Claims (1)

[Scope of Claims] 1. In a magnetic bubble memory element in which a bubble propagation path is formed on the surface of a bubble crystal by ion implantation, the ion-implanted bubble propagation path is located near a convex portion where a bubble is stopped by a holding magnetic field on the propagation path. A magnetic bubble memory element characterized in that a permalloy propagation element is arranged along the ion implantation propagation path. 2. Claim 1, characterized in that the gap between the permalloy propagation elements is equal to or larger than the bubble diameter.
The magnetic bubble memory device described in . 3. The magnetic bubble memory device according to claim 1 or 2, wherein the permalloy propagation device is asymmetrical with respect to the bubble propagation direction.