JPS5931149B2 - Magnetic bubble memory temperature detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic bubble memory temperature detection method.

The basic elements of the bubble chip that constitute the magnetic bubble memory device are to generate, erase, transfer and detect bubbles; for example, in generation, usually,
A pulsed current is passed through a hairpin-shaped conductor loop to locally form a nucleation magnetic field HN. Since the nucleation magnetic field HN has a temperature coefficient, it must be formed by flowing a current depending on the temperature of the chip itself.
Further, the optimum bias magnetic field that allows the bubble to stably exist in the chip also has a temperature coefficient, and therefore this magnetic field must be formed depending on the temperature of the chip. Furthermore, the size of the bubble diameter also affects the size of the temperature coefficient. Therefore, in order to measure the various characteristics of the bubble chip and to ensure that it operates well, it is necessary to accurately measure the temperature of the chip itself during operation. Conventionally, infrared thermometers, thermocouple meters, etc. have been used to measure the temperature of chips, but with the infrared thermometers mentioned above, the chip is housed in a magnetic bubble memory device and is not exposed to the outside, so measurements cannot be performed. It is possible.

In addition, the above method using a thermocouple meter not only requires extra space and wiring, but also has the drawback that the heat of the chip leaks out through the thermocouple, making it impossible to accurately measure temperature. . SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a device that is simple to operate, requires no extra space and wiring, and yet provides accurate temperature measurement.

In order to achieve such an object, the present invention has been developed so that the electrical resistivity of the metal thin film pattern formed on the chip for magnetic bubble detection or magnetic bubble control is ρ,
By using the fact that =ρ has a temperature dependence given by (1+α(, -),) and measuring the resistance value of the above pattern, the temperature of a single chip can be accurately detected. This will be explained in detail below using examples.

FIG. 1 is a plan view showing the entire bubble chip, in which 1 is a bubble generator, 2 is a transfer path, 3 is a replicator that divides and duplicates the bubble in the transfer path 2, and 4 is a bubble detector. This is a soft ferromagnetic magnetoresistive element such as permalloy, and as shown in FIG.
The replication bubble injected from the detector 4 is enlarged as it approaches the detector 4 via the element 21.
It is detected by an electrical signal when it reaches the point. In addition, in FIG. 1, 5 is a bonding pad. Therefore,
In such a configuration, bubbles are generated by the nucleation magnetic field HN generated by the bubble generator 1, transferred on the transfer path 2, replicated by the replicator 3, and detected by the detector 4. In this embodiment, the temperature of the chip nail body is detected by measuring the resistance value of the bubble detector 4. That is, the detector 4 is made by cutting a permalloy thin film into a fine pattern, and its resistance value is about 1KΩ. As a result of measuring the temperature dependence of the resistance value of this detector 4, the temperature coefficient α was 0.32%/°C, and this value was 10
It remained unchanged in the temperature range from °C to 50 °C. The temperature coefficient changes depending on the NI-Fe composition ratio of the permalloy thin film, but can be easily determined by measuring between pads using a constant temperature bath. This embodiment shows a method in which a pattern formed on a chip is used as it is as a thermometer, which is the best method for detecting the temperature of this bubble chip. In other words, it is possible to measure the temperature by separately forming a metal thin film pattern on the bubble chip and detecting the temperature by measuring the resistance of this pattern, but this method requires the cost of forming a separate metal thin film. Therefore, the method of the above embodiment is the best one. Although the above embodiment measures the resistance value of a metal thin film pattern for detecting magnetic bubbles, the present invention is not limited thereto. Of course, the temperature of the bubble chip may also be detected by measuring the resistance value of a metal thin film pattern for controlling magnetic bubbles, such as the one shown in FIG. As explained above, according to the present invention, a magnetic bubble detection device formed directly on a bubble chip,
Alternatively, the temperature of the bubble chip is determined by measuring the resistance value of a metal thin film pattern for controlling magnetic bubbles, such as a magnetic bubble replicator.

This eliminates the need for extra space and wiring, making it easy to measure.Moreover, since the metal thin film pattern is formed directly on the bubble chip, its resistance change reliably corresponds to the temperature change of the chip. The temperature obtained by resistance measurement is very accurate. Therefore, the temperature of any bubble chip incorporated in a magnetic bubble memory device is detected by the method according to the present invention, this temperature value is regarded as the temperature of the entire bubble chip, and the nucleation magnetic field is determined based on the magnitude of this temperature. By controlling the above, various characteristics of the bubble chip can be measured and the device itself can be operated properly. Note that among the bubble chips incorporated in the magnetic hub memory device, any bubble chip that should be used for temperature measurement may be selected that can operate normally. The temperature of the bubble chip to be discarded may be detected by incorporating it into the device.
This has the advantage of reducing costs when detecting temperature.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an outline of a magnetic bubble chip, and FIG. 2 is a plan view showing an example of a bubble detector. 1... Bubble generator, 2... Bubble transfer path, 3... Bubble replicator, 4... Bubble detector, 5...・Bonding pad.

Claims (1)

[Claims] 1. Detecting the temperature of the bubble chip by measuring the resistance value of a metal thin film pattern for magnetic bubble detection or control formed on the bubble chip loaded in the magnetic bubble memory device. A magnetic bubble memory temperature detection method featuring: