JPH01260372A - Deterioration diagnostic apparatus for electronic equipment - Google Patents

Abstract

PURPOSE:To judge the characteristic deterioration of an electronic equipment in a short time with a high sensitivity, by supplying the same diagnosis signal to a reference electronic equipment the same in function as an electronic equipment to be diagnosed to compute a probability variables density distribution of a fluctuation signal of signals thereof. CONSTITUTION:A diagnosing signal is supplied to an electronic equipment 22 to be diagnosed and a reference electronic equipment 23 from a signal source 21 and outputs 22a and 23a thereof are inputted into a fluctuation signal generating means 30 comprising a differential amplifier 31 and a band pass filter 32. Then, a fluctuation signal 30a as output thereof 30 is evaluated by a degrading diagnosis means 40 comprising a probability density distribution computing device 41, a reference setter 42, a comparison judging device 43 and a display output section 44 or a statistic processing method using a probability variable power spectrum, probability variables moment or the like. This enables the diagnosing of a fine change in characteristic in a short time and with a high sensitivity before causing a trouble.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a diagnostic device for diagnosing deterioration of electronic equipment.

[Conventional technology]

A digital device will be explained as an example of an electronic device.

Figure 4 shows, for example, the book “Design of Digital IC Circuits,”
1 is a diagram showing the configuration of a conventional diagnostic device for a digital device, which is described in "Author: Toshio Yuyama, published by GQ Publishing, March 1986." In the figure, (1) is the digital device to be diagnosed, (2) is the signal source that generates diagnostic signals and supplies them to the digital device (1), and (3) is the oscilloscope. The output of source (2) is connected and Ya
K is connected to the output of the digital device (1).

Next, the operation will be explained.

First, the signal source (2) generates a triangular wave-like signal whose magnitude changes from 0 to 5 (Vl) at a period of about 100 bar seconds as a deterioration diagnosis signal (2a), (1). This signal and the output signal of the digital device (1) that receives this signal and performs arithmetic operations are displayed on the tube surface of the oscilloscope (3) as a waveform as shown in Figure 5. Observed.

This waveform represents the threshold voltage, which is one of the characteristics of digital devices, that is, the switching voltage between 'H level and 'B level. By observing such a waveform, you can understand its characteristics and logical operation. Here, if the observer notices that the waveform is clearly different from the stored normal waveform, the observer subjectively diagnoses it as a failure or a defective product.

Further, as a defective product sorting device, there is a digital integrated circuit sorting device shown in FIG. 6 and described in Japanese Patent Application Laid-Open No. 117471/1983. In this method, the integrated circuit under test and a non-defective sample are operated with the same signal, and a comparison is made based on whether the output signals match.

[Problem to be solved by the invention]

Conventional diagnostic equipment for electronic devices is configured as described above, so it is possible to diagnose deterioration before it leads to failure or defect, such as when the characteristics such as the threshold voltage of the electronic device to be diagnosed are slightly different from the normal waveform. On the other hand, since logical operations are performed normally, it is difficult to objectively diagnose them by observing waveforms with an oscilloscope. In addition, it requires labor and time to manually diagnose each electronic device to be diagnosed, and furthermore, it is difficult to observe minute changes due to the limited resolution of an oscilloscope.

It should be noted that a device that compares and selects good products and defective products has a problem in that it is not possible to determine minute changes in characteristics.

The present invention was made in order to solve such problems, and an object of the present invention is to obtain a deterioration diagnostic device for electronic equipment that can diagnose minute changes in characteristics in a short time and with high sensitivity before a failure occurs. .

[Failure to solve the problem]

The deterioration diagnosis device for electronic equipment according to claim 1 of the present invention supplies the same diagnostic signal, which is a time function, to the electronic equipment to be diagnosed and the electronic equipment to be used as a reference for the same function, and performs the diagnosis. A fluctuation signal with a frequency component in a specific band is generated from the deviation value of the output signals of both military devices that have received the signal for calculation, and the random variable density distribution of this fluctuation signal is calculated, and this value is set in advance. The difference between the two values is compared with the reference value, and it is determined that the characteristics have deteriorated.

Further, according to claim 2, the random variable power spectrum of the fluctuation signal calculated in the same manner as in claim 1 is calculated, and this value is compared with a preset reference value, and the difference between the two values is calculated. This is to determine that the characteristics have deteriorated.

Furthermore, according to claim 3, the random variable moment of the fluctuation signal calculated in the same manner as in claim 1 is calculated, and this value is compared with a preset reference value, and the difference between the two values is calculated. This is to determine that the characteristics have deteriorated.

[Effect]

In the first aspect of the present invention, deterioration of characteristics is determined by comparing the magnitude of the random variable density distribution of the fluctuation signal of the output signal deviation value between the diagnostic target and the reference and the magnitude of the reference value.

Further, in the second aspect of the present invention, deterioration of the characteristics is determined by comparing the magnitude of the random variable power spectrum of the fluctuation signal with the magnitude of the reference value.

Furthermore, in the third aspect of the present invention, deterioration of the characteristics is determined by comparing the magnitude of the random variable moment of the fluctuation signal with the magnitude of the reference value.

〔Example〕

FIG. 1 is a diagram showing a configuration block of a deterioration diagnosing device for electronic equipment according to an embodiment of the present invention. In the figure, c! D is a signal source that supplies a diagnostic signal (21a), and the signal is a time function waveform whose magnitude changes with time, for example, an angular waveform with a period of about 100+ seconds. (2) is an electronic device to be subjected to deterioration diagnosis, and (2) is an electronic device to be used as a standard for deterioration diagnosis, which is of the same type as the one to be diagnosed or has the same function simulated by, for example, a computer model. ω is a part that generates a fluctuation signal (30a) having a frequency component in a specific band from the deviation signal between the output signal (22a) of the electronic device to be diagnosed (22a) and the output signal (23a) of the electronic device to be used as a reference. It consists of a differential amplifier (31) that amplifies the deviation of the respective output signals (22a) and (23a), and a bandpass filter (32) that passes a specific frequency component. Here, the frequency band to be passed by the band-pass filter (32) is determined depending on the type of electronic device to be diagnosed for deterioration + 22) and the frequency characteristics of the characteristics to be diagnosed. For example, the lower limit cutoff frequency fO is 001 (Hz). ), the upper limit cutoff frequency f1 is determined as 20 (Hz). At this time, the differential amplifier (31) and the bandpass filter (32)
As long as the frequency characteristics are the same, a differential amplifier can be connected after the bandpass filter, or a highpass filter, differential amplifier, and lowpass filter can be connected in this order. . The fluctuation signal (30a) thus generated will fluctuate in response to the diagnostic signal that changes over time if there is a slight difference in characteristics such as threshold voltage. Since this variation has the characteristics of a stationary random variable, it can be evaluated using the following three types of statistical processing methods. The first method is to evaluate using density distribution information within a predetermined region of random variables. The second method is to use the stationarity of random variables to evaluate using a power spectrum, which is information in the frequency domain that is Fourier expanded. The third method is to evaluate using the product moments of random variables, which are information such as short-term effective values that represent the dispersion of random variables and skewness that represents bias in the positive and negative directions.

Here, in FIG. 1, (40) is a deterioration diagnosis unit that evaluates the fluctuation signal (ternary) using the first method of the above-mentioned statistical processing methods. This deterioration diagnosis section (40) calculates the random variable density distribution of the fluctuation signal (30a), compares this value with a preset tolerance range, and diagnoses the deterioration of the characteristics based on the difference. a computing unit (41) that computes the density distribution; a comparison/judgment unit (43) that compares this value with the allowable range value of the standard setter (42) to determine characteristic deterioration;
, and a display/output section (44) that displays and outputs the results. At this time, the tolerance range of the standard setter (42) that is used as a standard for characteristic deterioration is determined by considering the required reliability of the target electronic device, for example, the random variable density of a plurality of electronic devices that are defined as normal. It may be set to the maximum value of the distribution or a value several times that value. In this way, minute deterioration in the characteristics of electronic equipment can be diagnosed objectively and with high sensitivity in a short time.

Next, FIG. 2 is a diagram showing a configuration block of a deterioration diagnosis device for electronic equipment according to an embodiment according to claim 2 of the present invention.
+211-■ is the same as in the above embodiment. (50
) calculates the power spectrum of the fluctuation signal (30a), which is a random variable, using the second statistical processing method described above, compares this value with a preset tolerance range, and detects the deterioration of the characteristics based on the difference. This is a deterioration diagnosis section that diagnoses. This deterioration diagnosis section (50) includes a calculator (51) that calculates a random variable power spectrum, and a comparison/determination device (53) that compares this value with the allowable range of a reference setting device (52) to determine characteristic deterioration.
, and a display/output section (54) that displays and outputs the results. Note that the allowable range of the standard setter (52), which is used as a standard for characteristic deterioration, may be set based on the same concept as in the above embodiment.

Furthermore, FIG. 3 is a diagram showing a configuration block of a deterioration diagnosis device for electronic equipment according to an embodiment according to claim 3 of the present invention,
c! (2) to (2) are similar to the above-mentioned embodiments. (6
0) calculates the product moments such as the rectangular time effective value and skewness of the fluctuation signal (30a), which is a random variable, by the third method of statistical processing described above, and calculates the product moments such as the rectangular time effective value and skewness of the fluctuation signal (30a), which is a random variable, and calculates the product moment such as the rectangular time effective value and skewness, and calculates the product moment such as the rectangular time effective value and skewness This is a deterioration diagnosing unit that compares the two and diagnoses the deterioration of characteristics based on the difference. This deterioration diagnosis section (60) includes a calculation unit (61) that calculates a random variable moment, and a reference setting device (62) that uses this value.
Comparison/judgment device (63) that determines characteristic deterioration by comparing it with the allowable range value of
4). The allowable range used as a criterion for characteristic deterioration at this time may also be set using the same concept as in the above-described embodiment.

In the description of each of the above embodiments, the threshold voltage of a digital device has been described as a characteristic of the electronic device whose deterioration is to be diagnosed, but it goes without saying that the present invention can also be used for other electronic devices.

〔Effect of the invention〕

As explained above, the present invention supplies the same diagnostic signal that is a time function to an electronic device to be diagnosed and an electronic device that has the same function as a reference, and receives this diagnostic signal λ. → A fluctuation signal having a frequency component in a specific band is generated from the deviation values of the output signals of the two military devices subjected to calculation operations, and in claim 1, the random variable density distribution of the fluctuation signal is generated, and in claim 2, In claim 3, a random variable power spectrum is calculated, and in claim 3, a random variable moment is calculated, and these values are compared with respective preset reference values to determine that the characteristics have deteriorated due to a difference between both values. This has the effect of diagnosing minute changes in characteristics in a short time and with high sensitivity before they lead to failures.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a configuration block of a deterioration diagnosis device for electronic equipment according to an embodiment of claim 1 of the present invention, and FIG. FIG. 3 is a diagram showing a configuration block of a deterioration diagnosing device for an electronic device according to an embodiment according to claim 3 of the present invention, and FIG. 4 is a diagram showing a configuration of a diagnosis section of a conventional digital device. , FIG. 5 is a diagram showing the operating waveforms of the device in FIG. 4, and FIG. 6 is a diagram showing the configuration of a conventional digital integrated circuit sorting device (where (211 is a signal source, is an electronic device to be diagnosed, 23) is an electronic device to be used as a reference, ω is a fluctuation signal generating means, (30a) is a fluctuation signal, (40), (
50). (6CI) is a deterioration diagnosis means. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (3)

[Claims] (1) A signal source that supplies the same diagnostic signal that is a time function to the electronic device to be diagnosed and the electronic device that should serve as a reference for the same function; Means for generating a fluctuation signal having a frequency component in a specific band from the deviation value of the output signals of both electronic devices, calculating the random variable density distribution of this fluctuation signal, and comparing this value with a preset reference value. A deterioration diagnosing device for electronic equipment, comprising a deterioration diagnosing means for determining that characteristics have deteriorated based on a difference in values. (2) A signal source that supplies the same diagnostic signal that is a time function to the electronic device to be diagnosed and the electronic device that should serve as a reference for the same function; A means of generating a fluctuation signal having a frequency component in a specific band from the deviation value of the output signal of an electronic device, calculating the random variable power spectrum of this fluctuation signal, comparing this value with a preset reference value, and calculating both values. 1. A deterioration diagnostic device for electronic equipment, comprising a deterioration diagnostic means for determining that characteristics have deteriorated based on a difference in characteristics. (3) A signal source that supplies the same diagnostic signal that is a time function to the electronic device to be diagnosed and the electronic device that should serve as a reference for the same function; A means of generating a fluctuation signal having a frequency component in a specific band from the deviation value of an output signal of an electronic device, calculating the random variable moment of this fluctuation signal, comparing this value with a preset reference value, and calculating both values. 1. A deterioration diagnostic device for electronic equipment, comprising a deterioration diagnostic means for determining that characteristics have deteriorated based on a difference in characteristics.