JPH01201893A - Magnetic bubble detector - Google Patents

Abstract

PURPOSE:To prevent bubbles from being excessively expanded and to eliminate the residual bubbles by making a conductor into a close loop condition and providing a detector in it in a current stretching system bubble detector having a bubble stretching conductor and a bubble detecting soft magnetic thin film detector. CONSTITUTION:A bubble detecting soft magnetic thin film detector 11 is formed on a magnetic bubble crystal 10, it is covered with a spacer 12 having the same size and shape as the crystal 10, and a bubble stretching conductor 13 is provided so as to sandwich the detector 11. Here, the conductor 13 is formed into a hair-pin shape having a cusp 15 of a bubble transferring path 14 as a folding point, and in order to satisfy a length necessary for bubble detection, one conductor 13a is folded to be the closed loop. To make the folded conductor 13a intersect to another conductor 13b, a through hole 18' is drilled through an insulating layer 17 on an extension line 16 and the conductor 13a, set beforehand, and they are connected with the use of a jumper line 19.

Description

[Detailed Description of the Invention] (Summary) The present invention relates to a magnetic bubble detector of a magnetic bubble memory element used in a storage device such as an electronic computing device, which prevents malfunctions due to incomplete erasure of bubbles after bubble detection, and improves the operating margin. For the purpose of expansion, in a current stretch type magnetic bubble detector equipped with a conductor for bubble stretching and a soft magnetic thin film detector for bubble detection, the conductor is formed into a closed loop, and the soft magnetic thin film detector is placed inside the conductor. Configure.

[Industrial application field]

The present invention relates to a magnetic bubble detector for a magnetic bubble memory element used in a storage device such as an electronic computing device.

A magnetic bubble memory element is a thin film of magnetic garnet (magnetic bubble crystal) formed by liquid phase epitaxial growth on a single crystal substrate of gadolinium, gallium, or garnet, for example.
A bubble transfer path is formed using a soft magnetic thin film such as permalloy on which a pattern such as a half disk type or asymmetrical chevron is arranged in matrix, or a contiguous disk type or snake type ion is formed by ion implantation. A bubble generator generates bubbles according to information and guides them to the transfer path, and if there is a bubble at a predetermined position in the pattern, it is "1".
If there is no such information, the information is stored as "0".

As the density of such magnetic memory elements increases, ion implantation elements that can be used for higher density are becoming mainstream. In addition, in bubble detection for information reproduction in this case, a pulse current is applied to a conductor such as a hairpin type to make bubbles stripe, and a thin film permalloy detector is used to detect current stretch using its magnetoresistive effect. method is the mainstream.

[Conventional technology]

FIG. 2 is a diagram showing a conventional current stretch type magnetic bubble detector. A hairpin conductor 1 for striping bubbles is arranged so that its hairpin loop is located at the cusp A of the ion implantation transfer path 2, and a soft magnetic thin film detector 3 for detecting bubbles is placed on the conductor 1. It is placed between two parallel lines. Then, when the bubble 4 is transferred and reaches the cusp A, a pulse having a stretch pulse C and a day stretch pulse D as shown in Fig. b is applied to the hairpin conductor 1,
After the bubbles are enlarged into striped magnetic domains and detected by the detector 3, the striped magnetic domains are returned to bubbles or erased.

(Problems to be Solved by the Invention) In the conventional current stretch type magnetic bubble detector described above, since one end of the hairpin type conductor 1 is open for terminal output as shown in FIG. The tip B of the magnetic domain 5 may extend from this opening and may remain even after daystretching, causing an error in which this remaining bubble is detected again in the next bit, and the error is particularly noticeable at the lower bias limit. There was a problem with becoming.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a current stretch type magnetic bubble detector that prevents errors caused by overstretching of bubbles.

[Means to solve the problem]

The above object is a current stretch type magnetic bubble detector equipped with a conductor for bubble stretching and a soft magnetic thin film detector for detecting bubbles, in which the conductor 13 is formed into a closed loop, and the soft magnetic thin film detector 11 is disposed therein. This is achieved by a magnetic bubble detector characterized by:

[For production]

By forming the conductor 13 for current stretching into a closed loop, when a pulsed stretching current is passed through the conductor 13, an attractive magnetic field is created inside the loop, and a repulsive magnetic field is created outside the loop. Can be done. Therefore, the bubble extends only within the loop and does not extend outside the loop, thereby preventing malfunctions due to over-extension of the bubble.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention, in which a is a plan view and b is a sectional view taken along line bb in FIG.

As shown in the figure, in this embodiment, a soft magnetic thin film detector 11 for detecting bubbles is formed on a magnetic bubble crystal 10.
A conductor 1 for bubble stretching is placed on top of the soft magnetic thin film detector 11 with a spacer 12 interposed therebetween.
3 is formed in a hairpin shape with the cusp 15 of the bubble transfer path 14 as a turning point, and the soft magnetic thin film detector 11
One of the conductors 13a is bent so that the hairpin-shaped conductor forms a closed loop at the point where it satisfies the length required to detect a bubble. Note that the point where the bent conductor 13a intersects the other conductor 13b is
A pre-provided lead wire 16 and one conductor 13a
Through holes 18, 18' are provided in the insulating layer 17 on top of the conductor 13a, and the conductor 13a and the lead wire 16 are connected by a jumper wire 19 formed by plating, which intersects the conductor 13b three-dimensionally.

In this embodiment configured as described above, an attractive magnetic field is generated inside the loop of the bubble stretch conductor 13 formed in a closed loop shape, and a repulsive magnetic field is generated outside the loop. The bubble being stretched does not extend outside the loop. Therefore, bubbles can be completely erased by the erase current after bubble detection, malfunctions at the lower bias limit are improved, and the operating margin of the detector is expanded.

〔Effect of the invention〕

As explained above, according to the present invention, in a current stretch type bubble detector, the conductor for bubble stretching is made into a closed loop shape to prevent bubbles from being overstretched and to prevent the generation of residual bubbles that occur when bubbles are erased. This eliminates malfunctions and expands the operating margin of the detector.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing a conventional current stretch type magnetic bubble detector, and FIG. 3 is a diagram for explaining the problem to be solved by the invention. In the figure, 10 is a magnetic bubble crystal, 11 is a soft magnetic thin film detector for bubble detection, 12 is a spacer, 13 is a conductor for bubble stretching, 14 is a bubble transfer path, 15 is a cusp, 16 is a lead wire, 17 is an insulating layer, 18 and 18'' are through holes, and 19 is a jumper wire.

Claims (1)

[Claims] 1. In a current stretch type magnetic bubble detector equipped with a bubble stretch conductor and a soft magnetic thin film detector for bubble detection, the conductor (13
) into a closed loop, and a soft magnetic thin film detector (
11) A magnetic bubble detector characterized in that: