JPS6023430B2 - magnetic bubble memory device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic bubble memory device, and more particularly to a magnetic bubble memory device with reduced capacitive coupling noise.

Generally, a magnetic bubble memory device includes a magnetic bubble memory chip consisting of a magnetic thin film and a pattern of a soft ferromagnetic thin film formed on the magnetic thin film, and lead wires for transmitting signals between the chip and an external circuit. It mainly consists of a coil block that applies a horizontal rotating magnetic field to the chip, and a magnet block that applies a bias magnetic field perpendicular to the chip, and generates magnetic bubbles in the pattern of the soft ferromagnetic thin film. , transfer, and divide the desired information to write, store, and issue information.

FIGS. 1a and 1b are a fragmentary plan view of a main part showing an example of a conventional magnetic bubble memory device, and a sectional view thereof taken along line A-A'.

In the figure, reference numeral 1 denotes an insulating substrate made of ceramic or the like, and a magnetic bubble memory element 2 is embedded and fixed approximately in the center of the insulating substrate 1.
Output signals from a magnetic bubble detector (not shown) in the magnetic bubble memory element 2 are transmitted through output signal wiring 3a, which is formed by a wiring pattern formed by coating a conductive member on the insulating substrate 1 by a method such as printing and coating. The terminals 3b are connected to output signal terminals 4a and 4b provided at the ends of the insulating substrate 1, respectively. Further, the insulating substrate 1 in which the magnetic bubble memory element 2 is housed has an X coil 5a in all directions of the x-axis and a Y coil 5b in the Y-axis direction on its outer peripheral surface side.
are wound perpendicularly to each other and supply a rotating magnetic field to the magnetic bubble memory element 2. In the magnetic bubble memory device configured in this way, minute magnetic bubble detection signals detected by the magnetic bubble detector in the magnetic bubble memory element 2 are transmitted via the output signal wirings 3a, 3b and the output terminals 4a, 4b. The signal is supplied to an external differential amplifier (not shown) and amplified, and a magnetic bubble memory output signal of about 4 mV is obtained by using the lid signal of the detection signal.

However, in the magnetic bubble memory device with the above configuration, the X coil 5a and Y coil 5a that generate the rotating magnetic field are
As shown in Fig. 2a, the distribution of voltage VL of the coil 5b with respect to the axis 0 direction (L direction) of the coil is uniformly increasing or uniformly decreasing as shown in Fig. 2b. It has a function.

On the other hand, the X coil 5a and Y coil 5b having different terminal voltage potential distributions are combined orthogonally in the X-axis direction and the Y-axis direction, respectively, and the output signal wirings 3a, 3
b is drawn out from the open end side of the X coil 5a and Y coil 5b. For this reason, X,
If there is a slight capacitance difference (imbalance of capacitive coupling) between the Y coils 5a, 5b and the output signal wiring 3a and between the X, Y coils 5a, 5b and the output signal wiring 3b, the output terminal 4a Capacitive coupling noise with different amplitudes is superimposed on the detection signal between the output terminal 4b and the output terminal 4b, and when the detection signal is amplified by the differential amplifier, the difference (unbalanced portion) of the capacitive coupling noise is amplified. , S of the magnetic bubble memory output signal
This method has disadvantages such as significantly lowering the /N ratio and making it extremely difficult to discriminate the output of the magnetic bubble memory. Therefore, an object of the present invention was to improve the above-mentioned drawbacks, and to provide a magnetic bubble memory device that reduces capacitive coupling noise and significantly improves the S/N ratio of the magnetic bubble memory output signal. Our goal is to provide the following.

In order to achieve such an object, the magnetic bubble memory device according to the present invention is configured such that the output signal wiring of the magnetic bubble memory element is drawn out from the low voltage side of the potential distribution of the rotating magnetic field generating coil.

The magnetic bubble memory device according to the present invention will be described in detail below with reference to the drawings. FIG. 3 is a plan view of essential parts showing an example of a magnetic bubble memory device according to the present invention,
Since the same symbols as in FIGS. 1a and 1b represent the same elements, their explanation will be omitted.

In the figure, 5a is the low voltage side of the potential distribution of the rotating magnetic field generating X coil 5a, and 5a2 is the high voltage side. Further, 50 is the low voltage side of the potential distribution of the rotating magnetic field generating Y coil 5b, and 5Q is the high voltage side. In the rotating magnetic field generating X and Y coils 5a and 5b configured in this way,
Sekiguchi section 5 constituted by low voltage sides 5a and 5b where the potential distribution of the terminal voltage of the X and Y coils 5a and 5b is low.
Output signal wiring 3 of the magnetic bubble memory element 2 from the c side
c and 3d are pulled out and connected to output terminals 4c and 4d. In other words, the rotating magnetic field generating X coil 5a, Y coil 5
Output signal wirings 3c and 3d consisting of a wiring pattern are formed on the insulating substrate 1 under observation on the opening side where the potential distribution of b is low. In the magnetic bubble memory device configured in this way, the × coil 5a and the Y coil 5 for generating a rotating magnetic field are used.
The opening □ part 5c of the low voltage side 5a, 5b, where the potential distribution of b is low
By pulling out the output signal wirings 3c and 3d from the side, the capacitive coupling noise generated on the output signal wirings 3c and 3d is reduced to about 1/10 or less compared to the secondary one, and the unbalance of the capacitive coupling is reduced. The noise level was reduced to 0.5 mV or less compared to the conventional 1.3 mV.

Therefore, the S/N ratio of the magnetic bubble memory output signal is greatly improved, and the output of the magnetic bubble memory can be easily determined. As explained above, according to the magnetic bubble memory device according to the present invention, the capacitive coupling noise caused by the coupling of the rotating magnetic field generating coils can be significantly reduced, and the S/N ratio of the magnetic bubble memory output signal can be significantly improved. It has excellent effects such as being able to significantly improve the quality and properties of a magnetic bubble memory device.

[Brief explanation of the drawing]

Figures 1a and b are a fragmented plan view of essential parts showing an example of a conventional magnetic bubble memory device, a sectional view taken along line A-A', and Figure 2a.
, b is a perspective view of a main part of a rotating magnetic field generating coil, and a potential distribution characteristic diagram thereof, and FIG. 3 is a fragmentary plan view of a main part showing an example of a magnetic bubble memory device according to the present invention. 1...Insulating substrate, 2...Magnetic bubble memory element, 3a, 3b, 3c, 3d...Output signal wiring, 4a, 4b, 4c, 4d... Output terminal, 5
a...×Coil, 5a.・・・・・・Low pressure side, 5a
2...High voltage side, 5b...Y coil, 5q.
...Low pressure side, 5Q...High pressure side, 5c...
Sekiguchi section. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. an insulating substrate, a magnetic bubble memory element disposed on the insulating substrate, an output signal wiring formed on the insulating substrate and transmitting a minute output signal of the magnetic bubble memory element, and the magnetic bubble memory. In a magnetic bubble memory device having at least a rotating magnetic field generating coil wound around the outer periphery of the element and supplying a rotating magnetic field to the magnetic bubble memory element, the output signal wiring is placed on the low voltage side of the potential distribution of the rotating magnetic field generating coil. 1. A magnetic bubble memory device characterized in that the capacitive coupling noise coupled from the rotating magnetic field generating coil to the output signal wiring is reduced.