JPH0519236B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magnetic bubble generator in a memory device that uses magnetic bubbles as information carriers. More specifically, the present invention relates to a magnetic bubble generator that nucleates magnetic bubbles using a local magnetic field generated by applying a current pulse to a conductor pattern.

(Prior art and its problems) Magnetic bubble memory devices that use magnetic bubbles as information carriers use a magnetic bubble generator that generates magnetic bubbles depending on the presence or absence of information, or a magnetic bubble generator that transfers the generated magnetic bubbles to a predetermined position. The magnetic bubble transfer path is the most important functional element. Recent magnetic bubble generators are, for example, developed by T.G. Nelson (T.J.
In 1980, Bell System
Technical Journal (The Bell System)
As shown on pages 229 to 257 of vol. 29. No. 2 (Technical Journal) vol. 29. No. 2, the magnetization in the magnetic bubble transfer path made of connected circular patterns of ion implantation tends to concentrate in a specific direction of the rotating magnetic field. It has a shape in which a hairpin-like conductor pattern is arranged, and magnetic bubbles are generated by the sum of the local magnetic field generated by applying a current pulse to the hairpin-like conductor and the local magnetic field from concentrated magnetization. ing.

The problems of such a conventional nucleation type bubble generator will be explained with reference to the drawings. FIG. 1A shows the same bubble generator as the conventional example described above. Magnetic bubble transfer paths 11 and 12 are formed by connected circular patterns 1 formed by ion implantation on a material that retains magnetic bubbles. A magnetic field generating hairpin conductor pattern 2 for the nucleation of magnetic bubbles is provided at a connecting cusp portion 10 of two circular patterns. Normally, a magnetic bubble is generated by applying a pulse current to the hairpin-shaped conductor 2 in a phase in which the in-plane rotating magnetic field H _R shown at 4 concentrates magnetization on the connecting cusp portion 10, so that the magnetic bubble 3 is generated in the connecting cusp portion 10. New creation occurs. However, this hairpin conductor pattern often shifts toward the connecting cusp portion 10' on the transfer path 12 side, as shown at 21, due to misalignment or the like. When a magnetic bubble generation current pulse is applied when the hairpin conductor pattern is deviated in this way, magnetic bubbles 3 are generated in the normal connecting cusp portion 10 at the same time as new creation.
Undesirable magnetic bubbles 31 often occur in the other articulating cusp 10', and these unwanted magnetic bubbles travel around the other transfer path 12 and cause malfunctions of the magnetic bubble elements.

On the other hand, FIG. 1B shows another conventional example of a magnetic bubble generator similar to the one presented by Hinata et al. in the Proceedings of the 1981 National Conference of the Institute of Electronics and Communication Engineers-226. In this second conventional example, the hairpin-shaped conductor pattern 2 is provided on the connecting cusp portion 10. On the other hand, the transfer pattern 1 formed by ion implantation has a large non-ion implantation pattern 15 on the opposite side of the connecting cusp portion 10. Therefore, even if some misalignment occurs, there is no possibility that extra magnetic bubbles will be generated in the transfer path 12 on the opposite side of the transfer path 11 of the transfer pattern 1. However, it is well known that if such a large non-ion implantation pattern exists near the connecting cusp portion 10, the transfer characteristics of the magnetic bubbles in the connecting cusp portion 10 will be extremely deteriorated. That is, the generated magnetic bubbles tend to stay at the generated connecting cusp portion 10, and therefore, this magnetic bubble generator has the disadvantage of being prone to malfunction.

(Objective of the Invention) An object of the present invention is to provide a magnetic bubble generator which eliminates the conventional drawback of being prone to malfunction and has good magnetic bubble generation and transfer characteristics.

(Structure of the Invention) According to the present invention, there is provided a nucleation type magnetic bubble generator in which a hairpin-like conductor pattern is arranged in the magnetization concentrated part of a magnetic bubble transfer path provided on a thin piece of magnetic material capable of holding magnetic bubbles. Accordingly, there is obtained a magnetic bubble generator characterized in that a magnetic bubble idler pattern is provided near the intersection of the magnetic bubble transfer path and the hairpin-shaped conductor pattern.

(Detailed Description of Configuration) The present invention solves the problems of the prior art by adopting the above-described configuration. The principle of the present invention is to first use a pattern shape that has excellent magnetic bubble transfer characteristics as a transfer pattern, and to prevent the occurrence of excess magnetic bubbles on the transfer path of the transfer pattern. In order to confine the excess bubbles in a specific location and prevent them from going to the normal transfer path, a magnetic bubble driving means such as a rotating magnetic field is sequentially applied at that specific location to cause the magnetic bubble to rotate idly for a short period of time. The aim is to prevent malfunctions due to the existence of an idler pattern, which is a transfer path.

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

Example 1 A first example of the present invention will be described with reference to FIG. A hairpin-shaped conductor pattern 2 is provided at a connecting cusp portion 10 in which magnetic bubbles are to be generated in a non-ion-implanted connected circular pattern 1 formed by ion implantation technology. That is, the hairpin conductor pattern 2 is arranged to intersect with the magnetic bubble transfer path 11 at the connecting cusp portion 10 . In order to maintain good magnetic bubble transfer characteristics, the above-mentioned articulating cusp part 10 connects the other articulating cusp part 10' facing the articulating cusp part 1 to the articulating cusp part 1.
It is necessary to place it near 0'. However, since the hairpin-shaped conductor pattern 2 is also arranged near the connecting cusp portion 10', unnecessary extra magnetic bubbles may be generated in the connecting cusp portion 10'.

However, this articulating cusp 10' is part of the magnetic bubble idler pattern 5 in accordance with the principles of the present invention. This idler pattern is formed by a small magnetic bubble transfer path surrounded by two continuous circular transfer patterns 50 arranged near the continuous cusp portion 10'. Unnecessary magnetic bubbles 3 generated from the hairpin-shaped conductor 2 in this idler pattern
1, according to the rotation of the in-plane rotating magnetic field shown in 4, the bubble only rotates in the small closed magnetic bubble transfer path 51 formed by the idler pattern, and does not go out to the other magnetic bubble transfer path 12. Therefore, there is no malfunction. Even if multiple magnetic bubbles occur in the idler pattern,
There is no need to worry because the bubble interaction is strong and one of them disappears.

Embodiment 2 FIG. 3 shows a second embodiment of the present invention. In this embodiment, the closed magnetic bubble transfer path 51 by the magnetic bubble idler pattern 5 is the same as in the previous embodiment. However, the difference is that the non-ion implantation pattern 50 forming the second transfer path 12 has an arcuate outer shape. Although the shape of the pattern forming the second transfer path has a considerable degree of freedom in this way, the effect of preventing malfunction of the magnetic bubble generator is not affected in any way.

Embodiment 3 FIG. 4 shows a third embodiment of the present invention. In this embodiment, a transfer path 1 on the periphery of a non-ion implanted pattern 1 is used.
No cusp portion exists on the opposite side of the cusp portion 10 that should generate one magnetic bubble. Instead, a circular ion implantation pattern is provided on the opposite side of the cusp portion 10, and the width of the cusp portion is formed to be narrow. For this reason, the magnetic bubble transfer characteristics in the transfer path 11 are maintained well. Furthermore, this circular ion implantation pattern plays the role of a magnetic bubble idler pattern 5. Therefore, unnecessary bubble 31
When this occurs, a closed transfer path 51 along the inside of the circular pattern is generated as the in-plane rotating magnetic field shown in 4 rotates.
It only circulates around the , and is not guided outside to the second transfer path 12 . That is, malfunction of the bubble generator does not occur. The normally generated magnetic bubble 3 is successfully transferred as described above.

Embodiment 4 FIG. 5 shows a fourth embodiment of the present invention. In this embodiment, the non-ion implantation pattern 1 is the same as in the first embodiment. However, hairpin-shaped conductor pattern 2
The shape of the conductor pattern is different, and a portion of the conductor pattern overlapping the cusp portion 53 on the opposite side of the connecting cusp portion 10' of the idler pattern 5 has a notch as shown at 23. If there is an unnecessary magnetic bubble 31 that has already been generated in the idler pattern 5, when the next magnetic bubble occurs, when the direction of the in-plane rotating magnetic field indicated by 4 points to the arrow 41, the hairpin conductor A current pulse 20 is applied to 2. At this time, the unnecessary magnetic bubbles 31 are present in the cusp portion 53 of the idler pattern, and are erased by the bias magnetic field component in the direction opposite to the bubble generation generated in the cut portion 23 of the hairpin conductor, so that the unnecessary bubbles in the idler pattern disappear. For this reason, the magnetic bubble generator according to this embodiment is less likely to malfunction.

Example 5 FIG. 6 shows a fifth embodiment of the present invention.

In this embodiment, the present invention is applied to the magnetic bubble transfer path 11.
This is applied to a magnetic bubble generator formed of a soft magnetic pattern 1 such as permalloy.

The hairpin-shaped conductor pattern 2 for generating magnetic bubbles is
It is provided in the bar-shaped soft magnetic pattern 5a which also serves as the transfer path 11 and a part of the idler pattern 5.
Normally, magnetic bubbles are generated within the hairpin 5a, but if extra magnetic bubbles are generated, the unnecessary magnetic bubbles 31 remain at the other end of the bar-shaped pattern 5a. However, as shown in the figure, a closed magnetic bubble transfer path 51 is constituted by the idler pattern 5 formed by the other three bar-shaped patterns 5b, 5c, and 5d, so that these unnecessary magnetic bubbles are It never returns to the regular transfer path 11, and malfunctions caused by the generation of unnecessary bubbles are reduced.

(Effects of the Invention) As described above, by using the present invention, a magnetic bubble generator that suppresses unnecessary generation of magnetic bubbles without impairing magnetic bubble transfer can be used for ion implantation devices as well. It can also be realized for devices that use magnetic material as a transfer pattern. Furthermore, the magnetic bubble generator of the present invention has an extremely high tolerance for misalignment between the hairpin-like conductor pattern and the transfer pattern. Therefore, if the magnetic bubble generator of the present invention is used, the process margin is large and the yield of devices can be improved.

[Brief explanation of the drawing]

FIGS. 1A and 1B are diagrams showing a conventional magnetic bubble generator. Figures 2, 3, 4, 5 and 6
The figure shows an embodiment of the magnetic bubble generator of the present invention. In the figure, 1 is a transfer pattern, 2 is a hairpin-like conductor pattern, 3 is a generated magnetic bubble, 4 is an in-plane rotating magnetic field, 5 is an idler pattern, 5a, 5b,
5c and 5d are patterns forming idlers, 1
0 and 10' are cusp parts, 11 and 12 are magnetic bubble transfer paths, 15 is a wide non-ion implantation pattern, 20 is the direction of current pulse, 21 is a misaligned hairpin-shaped conductor, 22 is inside the hairpin, and 23 is a A notch in the hairpin conductor, 31 an unnecessarily generated magnetic bubble, 41 an arrow indicating the direction of the rotating magnetic field, 50 a transfer pattern, 51 a closed magnetic bubble transfer path, 5
3 shows the cusp portion of the idler pattern.

Claims (1)

[Claims] 1. In a nu-creation type magnetic bubble generator in which a hairpin-shaped conductor pattern is arranged in the magnetization concentrated part of a magnetic bubble transfer path provided on a thin piece of magnetic material capable of holding magnetic bubbles, the magnetic bubble transfer path and the hairpin A magnetic bubble generator characterized in that a magnetic bubble idler pattern is provided near the intersection of shaped conductor patterns.