JPS60117471A - Magnetic bubble memory element - Google Patents

Abstract

PURPOSE:To increase a detection output by arranging one or more stages of stretcher patterns consisting of transfer patterns, which have pattern areas larger than those of bubble magnetic domain transfer patterns, in the succeeding stage of bubble magnetic domain detecting patterns. CONSTITUTION:The area of a stretcher pattern 3 just after a bubble magnetic domain detecting pattern 1 is made larger, and its period A is made longer than a period B of a preceding stretcher pattern 2. By this constitution, a bubble to be read out comes from the direction of an arrow 4 and is stretched by the stretcher pattern 2 to become a stripe magnetic domain, and this stripe magnetic domain is detected in the bubble magnetic domain detecting pattern 1 by using change of the magnetic resistance and is abandoned through the stretcher pattern 3. At this time, the bubble magnetic domain detecting pattern 1 is affected by a floating magnetic field generated by the stretcher pattern 3 just after this pattern 1 and increases the detection output.

Description

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

Conventional technology and problems Magnetic bubble memory utilizes the fact that magnetic bubbles can be moved freely within a magnetic thin film with uniaxial anisotropy by a magnetic field. For example, a magnetic garnet film is used as the magnetic thin film. , a bubble generator, a bubble transfer path for storing information, a bubble magnetic domain detector, etc. are formed on the surface thereof, and the presence or absence of bubbles is made to correspond to 111°lQf and information is stored.

Conventionally, the magnetoresistive effect of permalloy thin films has been used to detect bubble magnetic domains in such magnetic bubble memories. Normally, in order to obtain a sufficient signal voltage for the sense amplifier, a large number of transfer patterns such as chevron patterns, called a stretcher, are arranged in parallel and are stretched to perform detection. On the other hand, when such a stretcher pattern is placed near the detector, there is a problem in that the stray magnetic field generated by the stretcher pattern itself changes the sense waveform of the Shibapur magnetic domain, affecting detection efficiency.

OBJECTS OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to provide a magnetic bubble memory element that can obtain a large detection output by actively utilizing the floating magnetic field created by the stretcher pattern.

According to the present invention, a plurality of bubble magnetic domain transfer patterns made of soft magnetic material are arranged in a direction perpendicular to the bubble traveling direction to form a stretcher pattern, and the stretcher pattern is arranged in the bubble traveling direction. In a magnetic bubble memory element comprising a bubble magnetic domain detector consisting of a plurality of stages of bubble magnetic domain stretchers and a bubble magnetic domain detection pattern that detects bubble magnetic domains stretched by the bubble domain stretchers using a magnetoresistive effect. , the bubble magnetic domain detector is a magnetic bubble memory element characterized in that one or more stages of stretcher patterns each formed by a transfer pattern having a larger pattern area than the bubble domain transfer pattern are arranged after the bubble magnetic domain detection pattern. This is achieved by providing

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

FIG. 1 is a diagram for explaining the present invention in detail, and the figure shows the same bubble magnetic domain detector with only the stretcher pattern changed to a period of 10.5 μm and a period of 15 μm.
．． It is a diagram showing the detection efficiency of 9 μm bubbles determined through experiments.

In the figure, the horizontal axis is the driving magnetic field, and the vertical axis is the detection efficiency I.
R/R (where R is the resistance of the bubble magnetic domain detection pattern, ΔR
Curve A shows the case where the stretcher pattern has a period of 15 μm, and curve B shows the case where the stretcher pattern has a period of 10.5 μm. As can be seen from the figure, even though the same detector is used, the detection efficiency changes considerably depending on the shape of the stretcher pattern.Moreover, if the stretcher pattern has a long period,
The larger the permalloy volume, the greater the output. On the other hand, with the increase in the density of bubble memory elements, the bubble diameter has increased to 1
．． As the size becomes smaller than 5 μm, in a pattern in which the volume of permalloy is increased with too long a period, the elongated stripe magnetic domain is divided into short sections within the stretcher pattern, and the output decreases.

FIG. 2 is a diagram for explaining a bubble magnetic domain detector in a magnetic bubble memory element according to the present invention. In the figure, 1 is a bubble magnetic domain detection pattern, 2 and 3 are stretcher patterns, and arrow 4 is a bubble traveling direction. are shown respectively.

In this embodiment, as shown in FIG. 2, the period A of the stretcher pattern 3 immediately after the bubble magnetic domain detection pattern 1 is made larger than the period B of the normal stretcher pattern 2 (that is, the stretcher pattern immediately before the bubble magnetic domain detection pattern). be.

In this embodiment configured as described above, the bubble to be read comes from the direction of the arrow 4 and is stretched by the stretcher pattern 2 to become a striped magnetic domain, and the striped magnetic domain is detected by the bubble domain detection pattern 1 to detect changes in magnetic resistance. After being utilized and detected, it passes through the stretcher pattern 3 and is discarded. At this time, the bubble magnetic domain detection pattern 1 is influenced by the floating magnetic field created by the stretcher pattern 3 immediately after it, and its detection output increases. In addition, since stretcher pattern 2 with a short period is used to stretch the bubble magnetic domain before detecting the bubble magnetic domain, the striped magnetic domain that has been stretched 1 to 1 is not divided, but the striped magnetic domain is divided in the stretcher pattern 3. However, in this case, since it is after passing through the bubble magnetic domain detection pattern 1, it does not affect the device characteristics.

FIG. 3 is a diagram showing another embodiment, in which the second
The same parts as in the figures are indicated with the same reference numerals.

This example is different from the previous example in that not only the period of the stretcher pattern 3 immediately after the bubble magnetic domain detection pattern is increased, but also the volume of permalloy is reduced by connecting adjacent patterns. It also increased the number of people. Therefore, in this embodiment, since the volume of permalloy is further increased, the floating magnetic field created by the stretcher pattern 30 becomes stronger, and the detection output can be further increased.

Effects of the Invention As described in detail above, the magnetic bubble memory element of the present invention improves the detection output of bubble magnetic domains by changing the pattern period of the stretcher pattern of the bubble magnetic domain detector to 9 before the bubble magnetic domain detection pattern. [It is also highly effective.]

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the principle of a bubble magnetic domain detector in a magnetic bubble memory element according to the present invention, and FIG. 2 is a diagram for explaining an embodiment of a bubble magnetic domain detector in a magnetic bubble memory element according to the present invention. , FIG. 3 is a diagram for explaining another embodiment. In the drawings, 1 indicates a bubble magnetic domain detection pattern, 2 indicates a stretcher pattern immediately before the bubble magnetic domain detection pattern, and 3 indicates a stretcher pattern immediately after the bubble magnetic domain detection pattern. Fig. 1 40 50 (a) Drive magnetic field (○e) N to l f-1 1 arrogant ('') 1 -1 to 1 arrogant

Claims (1)

[Claims] 1. A bubble magnetic domain stretcher in which a plurality of bubble magnetic domain transfer patterns formed of a soft magnetic material are arranged in a direction perpendicular to the bubble traveling direction to form a stretcher pattern, and the stretcher patterns are arranged in multiple stages in the bubble traveling direction; In a magnetic bubble memory element equipped with a bubble magnetic domain detector similar to a bubble magnetic domain detection pattern that detects a bubble magnetic domain stretched by a bubble magnetic domain stretcher using a magnetoresistive effect, the bubble magnetic domain detector has a bubble magnetic domain detection pattern. 1. A magnetic bubble memory device, characterized in that one or more stages of stretcher patterns each formed by a transfer pattern having a larger pattern area than the bubble magnetic domain transfer pattern are disposed downstream of the pattern.