JP3400362B2 - Method and apparatus for diagnosing life of electronic device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention allows maintenance personnel to non-destructively maintain the function of the electronic device to be diagnosed at the site where the electronic device to be diagnosed is delivered and to reduce the remaining life of the electronic device used over the years. The present invention relates to a method and apparatus for diagnosing a life of an electronic device that can be quantitatively evaluated.

[0002]

2. Description of the Related Art In the field of abnormality diagnosis of electronic devices including measuring instruments and control devices installed in electric power plants and industrial plants, the input / output characteristics of each electronic device are measured and monitored in time series and rated. A method of detecting an abnormality in an electronic device online by comparing with a value or an initial value is generally used.

On the other hand, in the field of life diagnosis in which the deterioration tendency of an electronic device is detected and the life period thereof is judged, deterioration can be easily detected by the above-mentioned online technique for checking the input / output characteristics of the electronic device. Since it is difficult, it is necessary to detect with high sensitivity the physical and physical deterioration signals such as heat generation and corrosion of the electronic control board and electronic components that make up the electronic device. Therefore, as a method of catching the deterioration with high sensitivity, the surface temperature of the computerized control board that constitutes the electronic device to be diagnosed is measured by an infrared sensor, or the electronic parts mounted on the electronic device are detached and their electrical characteristics ( Input / output characteristics, marginal voltage, internal noise, etc.) are checked, or the resin-sealed IC is removed to evaluate the amount of Al wiring corrosion, and the remaining life is quantitatively estimated from those time-series change curves. Has been done so far.

[0004]

In the conventional life diagnostic technology for electronic devices, in order to detect the tendency of deterioration of the electronic device,
The mounted parts are removed from the electronic control board that constitutes the electronic device, that is, the electronic device is destroyed, and then the removed electronic part is taken from the field to a research department such as a factory or a research laboratory, and performance deterioration of the electronic part I was looking for corrosion.

Actually, in a life diagnosis method using Al wiring corrosion of a resin-encapsulated IC as a deterioration index, the resin is unsealed with a chemical solution to quantitatively evaluate Al wiring corrosion, and a surface photograph of the IC chip is taken. , This must be image-diagnosed. Therefore, it is impossible to carry out the diagnosis locally and non-destructively. However, there is a demand on the part of the user of the electronic device to continue to use the electronic device when performing life diagnosis without impairing the function of the electronic device to be diagnosed and finding that the remaining life is sufficient. .

The present invention has been made in consideration of such circumstances. First, it is possible to quantitatively and easily evaluate the remaining life of an electronic device easily and accurately without destroying the function of the electronic device. Secondly, the present invention provides a method and a device for diagnosing the life of an electronic device, which allows maintenance personnel to easily measure the diagnostic parameters at the time of off-line such as at the time of periodic inspection, and can determine the remaining life on site. The purpose is to

[0007]

In order to solve the above problems, the method of diagnosing the life of an electronic device according to claim 1 is an object to be diagnosed when diagnosing the life of an electronic device including an instrument and a control device. The total number of computerized control boards that make up the electronic device is divided into a plurality of groups so that the number of each group is substantially equal, and some groups are arbitrarily extracted from the divided areas to measure the substrate material performance. By performing extreme value statistics of the distribution of the measured values of the substrate material performance in each group, the minimum or maximum value of the substrate material performance values of all the substrate parameters in the diagnosis target is estimated, and the time series change of this estimated value is performed. The gist of the present invention is to quantitatively evaluate the remaining life of the computerized control board from the limit value defined by a predetermined standard of the board material performance value. With this configuration, the substrate material performance measurement value of the electronic control board is adopted as a diagnostic parameter for diagnosing the life of the electronic device, and the substrate material performance measurement is performed for some groups arbitrarily extracted from all the electronic control boards. . The extreme value of the substrate material performance value in the entire substrate parameter constituting the diagnosis target is estimated using the extreme value statistical method for the substrate material performance measurement value in each group. Then, a point where the estimated time series change curve of the extreme value exceeds the limit value defined by a predetermined standard such as JIS standard is quantitatively evaluated as a life point.

An electronic device life diagnosing method according to a second aspect is the electronic device life diagnosing method according to the first aspect, in which the minimum or maximum estimated value of the substrate material performance value of the computerized control substrate is estimated. Based on the correlation curve between the corrosion amount of the IC mounted on the computerized control board and the corrosion amount of the IC mounted on the electronic control board, the corrosion amount of the mounted IC is calculated nondestructively from the estimated value of the substrate material performance.
The gist of the present invention is to evaluate the remaining life of the electronic control board by quantitatively estimating the remaining life of the mounted IC from the time series change of the C corrosion quantity and the correlation between the corrosion quantity and the IC failure. With this configuration, by knowing the type of the electronic control board and the type of the mounted IC, the correlation curve between the substrate material performance value and the IC corrosion amount obtained in advance is used to measure the corrosion amount of the mounted IC from the measured substrate material performance value. Is required. Next, the remaining life of the mounted IC is quantitatively estimated from the amount of corrosion leading to the IC failure, and the remaining life of the electronic control board is evaluated.

According to a third aspect of the present invention, there is provided a method for diagnosing the lifetime of an electronic device, wherein the method for diagnosing the lifetime of the electronic device is the estimated value of the minimum or maximum value of the substrate material performance value of the computerized control substrate and the estimated value. Based on the correlation curve with the performance value of the capacitor mounted on the computerized control board, the performance value of the mounting capacitor is calculated nondestructively from the estimated value of the board material performance. The gist of the present invention is to quantitatively estimate the remaining life of the mounted capacitor from the failure judgment standard and evaluate the remaining life of the electronic control board. With this configuration, by knowing the type of computerized control board and the type of mounted capacitor, the correlation curve between the board material performance value and the capacitor performance value such as capacitance, dielectric loss tangent or insulation resistance that was obtained in advance can be used to The performance value of the mounted capacitor can be obtained from the measured material performance value. Then
The remaining life of the mounted capacitor is quantitatively estimated from the time-series change of the performance value of the mounted capacitor and the failure judgment criterion of the capacitor, and the remaining life of the electronic control board is evaluated.

According to a fourth aspect of the present invention, there is provided an apparatus for diagnosing life of an electronic device, comprising: a substrate material performance measuring means for measuring a substrate material performance value of an electronic control board constituting the electronic device to be diagnosed.
Structure for measuring substrate material performance, measurement value correcting means for correcting the measurement value by the substrate material performance measuring means when the measurement conditions including pretreatment are different from the standard defining the limit value of the substrate material performance, and the measured value Extreme value statistical processing means for executing extreme value statistical processing on the substrate material performance value after correction by the correcting means, time series change of the minimum and maximum values of the substrate material performance value obtained by the extreme value statistical processing means, and the substrate Life determining means for determining the remaining life from the limit value of material performance, correction data for performing the correction, the limit value for life determination, a database holding the extreme value statistical processing result and the determination result, The gist is to have an output means for displaying a series of diagnostic results. With this configuration, even when the substrate material performance measurement is performed in a form different from the standard that defines the limit value of the substrate material performance when measuring the substrate material performance value by the substrate material performance measurement means, the substrate material performance value is measured by the measurement value correction means. Is corrected to the value measured under the standard. Since the extreme value statistical processing means performs the extreme value statistical processing on the substrate material performance values, the minimum and maximum values of the substrate material performance values in the diagnosis target can be estimated without measuring the substrate material performance values of all the substrates. . Then, the life determining unit determines the remaining life from the estimated time series change of the extreme value and the limit value defined by a predetermined standard. Further, since the diagnosis case is stored in the database, it can be applied as a diagnosis dictionary.

According to a fifth aspect of the present invention, there is provided an electronic device life diagnosing device according to the fourth aspect of the invention.
Minimum of the substrate material performance value obtained by the extreme value statistical processing means
Corrosion amount conversion means for converting the maximum value into the corrosion amount of the IC mounted on the electronic control board based on the substrate material performance value-corrosion amount correlation curve for each IC type is provided, and the life determination means is provided. The quantitative evaluation of the remaining life of the mounted IC based on the corrosion amount conversion result by the corrosion amount conversion means and the time-series change curve of the corrosion amount for each IC type, the database stores various board material performance values, The gist is to accumulate the substrate material performance value-corrosion amount correlation curve for each IC type and the time series change curve of the corrosion amount for each IC type. With this configuration, if the type of the electronic control board and the type of the mounted IC are known, the corrosion amount conversion means estimates the progress of corrosion of the mounted IC from the substrate material performance measurement value. Then, by the life determining means,
The remaining life of the mounted IC is quantitatively evaluated from the amount of corrosion leading to the IC failure. A substrate material performance value-corrosion amount correlation curve or the like for estimating the corrosion progress of the mounted IC from the substrate material performance measurement value by the corrosion amount conversion means is obtained from the database.

According to a sixth aspect of the present invention, there is provided an electronic device life diagnosing device according to the fourth aspect of the invention.
Minimum of the substrate material performance value obtained by the extreme value statistical processing means
The maximum value, the substrate material performance value for each capacitor-capacitor performance conversion means for converting to the performance value of the capacitor mounted on the electronic control board based on the capacitor performance correlation curve, the life determining means, , Quantitatively evaluating the remaining life of the mounted capacitor based on the conversion result of the capacitor performance value by this capacitor performance conversion means and the time series change curve of the performance value for each capacitor type, and the database stores the performance value of various board materials. The summary is to accumulate a substrate material performance value-capacitor performance correlation curve for each capacitor type and a time series change curve of the performance value for each capacitor type. With this configuration, if the type of the electronic control board and the type of the mounted capacitor are known, the progress of performance deterioration of the mounted capacitor is estimated from the board material performance measurement value by the capacitor performance conversion means. Next, the life determining means quantitatively evaluates the remaining life of the mounted capacitor from the performance deterioration leading to the capacitor failure. A board material performance value-capacitor performance correlation curve or the like for estimating the progress of performance deterioration of the mounted capacitor from the board material performance measurement value by the capacitor performance conversion means is obtained from the database.

An electronic device life diagnosing device according to a seventh aspect is the electronic device life diagnosing device according to the fourth, fifth or sixth aspect, wherein the substrate material performance measuring means comprises an insulation resistance measuring device. The gist is to measure the volume resistivity or surface resistance of a part of the electronic control substrate. With this configuration, the board material performance is set to a volume resistivity or surface resistance that can be easily measured even in an electronic control board that has a small space other than the mounting part, and the board material performance measuring means for measuring this is insulation resistance measurement. The device. By using an insulation resistance measuring device, local maintenance personnel can easily carry and measure it at the time of periodic inspections.

An electronic device life diagnosing device according to claim 8 is the electronic device life diagnosing device according to claim 4, 5 or 6, wherein the substrate material performance measuring means comprises a capacitance measuring device, A part of the electronic control board is sandwiched by electrodes to form a capacitor using the electronic control board as a dielectric, and the capacitance is measured to calculate the dielectric constant of the electronic control board. And With this configuration, the board material performance is set to a capacitance that can be easily measured by a part of the electronic control board that has a small space other than the mounting portion. It is used as a measuring device. By using the capacitance measuring device, it becomes possible for a local maintenance person to easily carry and measure it at the time of periodic inspection.

According to a ninth aspect of the present invention, there is provided an electronic device life diagnosing device according to the fourth, fifth or sixth aspect, wherein the substrate material performance measuring means comprises a color measuring system. The gist is to evaluate the strength of the solder at the soldering site on the chemical control board as the color of the solder. With this configuration, the substrate material performance is set as the color of the solder for evaluating the strength of the solder, and the color of the solder is measured by the color measurement system in a non-contact and non-destructive manner.

An electronic device life diagnosing device according to a tenth aspect of the present invention is the electronic device life diagnosing device according to any one of the fourth to ninth aspects, in which the electrical performance and mechanical performance of the substrate material performance measuring means are determined. In order to be able to measure the substrate material performance including the above, the gist is that a substrate material performance measuring test piece according to a required standard is previously incorporated in a part of the electronic control substrate. With this configuration, it becomes possible to take out the test piece for measuring the substrate material performance at the time of regular inspection and to measure the substrate material performance in accordance with a desired standard. This enables measurement without impairing the function of the electronic device.

According to the eleventh aspect of the present invention, there is provided a method for diagnosing the life of an electronic device, wherein when diagnosing the life of an electronic device including a measuring instrument and a control device, the electronic device is manufactured on a computerized control board constituting the electronic device to be diagnosed. At this time, a ceramics humidity sensor for diagnosis is mounted in advance, the resistance value change of the ceramics humidity sensor is measured, and the resistance value of the ceramics humidity sensor and the characteristic value of the mounted component mounted on the electronic control board are measured. The gist is to estimate the degree of deterioration of the mounted components mounted on the computerized control board from the correspondence and evaluate the remaining life of the computerized control board. With this configuration, the degree of deterioration of the mounted component is estimated from the change in the resistance value of the ceramic humidity sensor, and the remaining life of the electronic control board is evaluated.

According to a twelfth aspect of the present invention, there is provided a method for diagnosing the life of an electronic device, wherein when diagnosing the life of an electronic device including an instrument and a control device, it is mounted on an electronic control board constituting the electronic device to be diagnosed at the time of manufacturing. A ceramics humidity sensor for diagnosis is mounted in advance, the resistance value change of the ceramics humidity sensor is measured, and the correspondence between the resistance value of the ceramics humidity sensor and the corrosion amount of the IC mounted on the electronic control board is measured. From the above, the amount of corrosion of the mounted IC mounted on the computerized control board is estimated, and the remaining life of the computerized control board is evaluated. With this configuration, the corrosion amount of the mounted IC is estimated from the change in the resistance value of the ceramics humidity sensor to evaluate the remaining life of the electronic control board.

According to a thirteenth aspect of the present invention, there is provided a method for diagnosing a life of an electronic device, wherein, when diagnosing the life of an electronic device including an instrument and a control device, it is mounted on an electronic control board constituting the electronic device to be diagnosed at the time of manufacturing. A ceramics humidity sensor for diagnosis is mounted in advance, the resistance value change of the ceramics humidity sensor is measured, and the correspondence between the resistance value of the ceramics humidity sensor and the performance value of the capacitor mounted on the electronic control board is measured. From the above, the gist is to estimate the performance value of the mounting capacitor mounted on the computerized control board and evaluate the remaining life of the computerized control board. With this configuration, performance values such as capacitance, dielectric loss tangent or insulation resistance of the mounted capacitor are estimated from changes in the resistance value of the ceramics humidity sensor to evaluate the remaining life of the computerized control board.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The essence of the present invention is that, in the life diagnosis of an electronic device, the board material performance of the electronic control board (printed wiring board) constituting the electronic device and the characteristics of the mounted parts are
Non-destructive measurement or estimation without impairing the function of the electronic device, and the extreme value statistical method is used to derive the extreme value of the substrate material performance as a diagnostic parameter, and the sampling number is minimized to reduce the measurement work in diagnosis. This will enable on-site life diagnosis.

Hereinafter, embodiments of the present invention based on the above concept will be described in detail with reference to the drawings.

FIGS. 1 and 2 are a flow chart and a concrete procedure for explaining the first embodiment of the method for diagnosing the life of an electronic device according to the present invention. This embodiment will be described with reference to these drawings. Before performing the substrate material performance measurement, first, the total number of computerized control boards constituting the diagnosis target is grasped and divided into a plurality of groups so that the numbers of the respective groups are substantially equal (step 10).
1). Some groups are arbitrarily extracted from the divided groups (step 102), and the substrate material performance is measured for the extracted groups (step 103). Examples of the substrate material performance to be measured include surface resistance, volume resistivity, dielectric constant, solder joint strength, etc. of the printed wiring board.
These substrate material performances may be monitored online, but since they do not change suddenly and are thought to occur with aging, the target substrate should be pulled off during offline inspections such as during periodic inspections and non-destructive at the site. taking measurement.
If there is no particular deterioration as a result of the measurement, it is realistic to return the product to the product after regular inspection and use it normally. Here, at the time of measuring the substrate material performance, it is judged whether or not the measuring method and conditions conform to the standard that defines the limit value of the substrate material performance at the time of evaluating the remaining life described later (step 104). ). Since this standard defines the measurement method of substrate material performance, pretreatment conditions, etc., it is necessary to perform the measurement according to the measurement method and conditions according to the adopted standard. If the specified conditions cannot be met when the substrate material performance is measured locally during regular inspections,
The measurement value is corrected (step 105). The correction is
Differences in measured values due to differences in measurement methods and differences in substrate material performance values due to the presence or absence of pretreatment are stored in a database for each target material and regulation, and correction data is called from the database when necessary. An extreme value statistical process is performed on the measured substrate material performance value or the corrected substrate material performance value, and the extreme value (maximum or minimum value) of the material performance value in all the substrates constituting the diagnosis target is estimated (step 106). . Specifically, the procedure is as shown in FIG.
The data is collected for each extracted group, and the extreme value of the measured value in each group is obtained. If the obtained extreme value of each group is the maximum value, it is sorted in ascending order, and if it is the minimum value, it is sorted in descending order,
This is plotted on the Gumbel probability paper. Estimate the extreme value of the substrate material performance for the total number of substrates in the diagnosis target from the intersection of the regression approximation line of the plotted points and the recurrence period, and if this value is out of the standard, the electronic control board that constitutes the diagnosis target The entire set of is irrelevant. The remaining life is estimated by examining the time series change of the extreme values of all the boards, and this time series change curve is
By defining a point that exceeds the limit value (threshold value) (step 107) defined by a desired standard read from the database as a life point, it can be quantitatively performed (step 108). That is, although the surface resistance, volume resistivity, solder joint strength, etc. of the electronic control board decrease with deterioration, they must be kept above a certain lower limit. Therefore, the minimum value in all the target substrates is estimated by the extreme value statistical method, and the point at which this value falls below the threshold value is the life. On the other hand, the dielectric constant must be kept below a certain upper limit with respect to the rise due to deterioration. Therefore, the maximum value in all the target substrates is estimated by the extreme value statistical method, and the point at which it exceeds the threshold is set as the life. The evaluation result of the remaining life is output to a monitor, a printer, a storage device, etc. (step 109).

FIGS. 3 to 6 are views showing a first embodiment of a life diagnostic device for an electronic device according to the present invention. The electronic device life diagnosing apparatus according to the present embodiment corresponds to an apparatus for executing the first embodiment of the electronic device life diagnosing method. First, the overall configuration will be described with reference to the block diagram of FIG. An electronic device life diagnosis device 1 measures a substrate material performance measuring means 2 for non-destructively measuring substrate material performance in an empty space on an electronic control substrate, and a substrate material performance measurement condition when the conditions cannot meet a desired standard. A measured value correction means 3 for correcting the data, and an extreme value statistical processing means 4 for estimating the extreme value of the substrate material performance value with respect to the total number of computerized control boards constituting the diagnosis object from the measured or corrected substrate material performance value,
Correction data for correcting the measured values of board material performance, database 5 that accumulates a life diagnosis algorithm for each diagnostic object type and diagnosis parameter (measurement board material performance type), and the life diagnosis algorithm is read from database 5 to determine the remaining life. It is composed of a life determining means 6 for quantitatively evaluating and an output means 7 for outputting a diagnosis result and the like.

Next, an insulation resistance measuring device, a capacitance measuring device and a color measuring system, which are specific examples of the substrate material performance measuring means 2, will be described in order with reference to FIGS. 4, 5 and 6.

FIG. 4 shows the substrate material performance measuring means 2.
The example which used the insulation resistance measuring device 12 is shown. When measuring the surface resistance and volume resistivity of the electronic control board 11 as the board material performance, the insulation resistance measuring device 12 is used. A circular electrode was created on the non-mounting part (empty space) 11a on the electronic control board 11 at the time of measurement with conductive silver paint or adhesive copper foil, and in the volume resistance measurement, the inner circle 13a of the upper electrode and the lower electrode 13c were formed. In the surface resistance measurement, a voltage is applied between the inner circle 13a and the outer circle 13b of the upper electrode. Then, the volume resistance and the surface resistance are measured by a comparison method or the like with respect to the standard resistor R _s as shown in the circuit diagram. Volume resistivity ρ _v
Is calculated according to the following formula. ρ _v = (πd ² / 4t) · R _v (1) d: outer diameter of inner circle of upper electrode t: substrate thickness R _v : volume resistance

FIG. 5 shows the substrate material performance measuring means 2.
An example using the capacitance measuring device 14 is shown. When measuring the permittivity or dielectric loss tangent of the electronic control substrate 11 as the substrate material performance, the capacitance measuring device 14 is used. Similar to the insulation resistance measurement, circular electrodes 15a and 15b are formed on the non-mounting part (empty space) 11a on the electronic control board 11 with conductive silver paint or adhesive copper foil,
The electronic control board 11 to form the capacitor C _x with a dielectric. This is connected to the position of C _x of the transformer bridge method measuring circuit which is the capacitance measuring device 14, and the variable capacitor C _s for measurement and the conductance shifter g are adjusted to C when the bridge is balanced. The value of _s , the conductance S, l between m and d of the conductance shifter g
The resistance value between −m and the resistance value between m and r are measured. Then, the dielectric constant ε and the dielectric loss tangent tan δ are calculated by the following formulas.

[0027]

## EQU1 ## ε = C _x / C ₀ (2) C _x : capacitance C ₀ of the measuring capacitor C _s when the bridge is in balance: ε calculated from the area of the main electrode and the thickness of the insulating substrate
= 1 capacitance C ₀ = r ² /3.6t r: radius of main electrode, t: thickness of substrate tan δ = G _x / (2πf · C _x ) ... (3) G _x : of insulating substrate Conductance G _x = G · (S / 100) S: Conductance between m and d of the conductance shifter S / 100: Resistance ratio at the equilibrium point of the conductance shifter f: Measurement frequency

FIG. 6 shows, as the substrate material performance measuring means 2,
The example which uses the color measuring system which evaluates the strength of the solder of a soldering part as a color of a solder is shown. When evaluating the strength of the solder at the soldering site as the board material performance, the color measurement system 16 is used. Light is made to enter / reflect at a certain soldering portion on the electronic control board 11 by the taking-in optical system 16a, reflected light is measured by a measuring system 16b such as a CCD camera, and the color value of the solder is analyzed by a processing system 16c. . XY stage 16d and capturing optical system 1
The optical path is adjusted so that the desired portion can be observed at 6a. The processing system 16c derives the solder strength from the measured optical signal based on the correlation between the solder strength and the solder color value as shown in the graph of FIG. 6B.

If the test piece for measuring the above-mentioned substrate material performance characteristics is incorporated in advance on the electronic control board in a form independent of the circuit of the electronic device, the measurement conforming to the desired standard can be carried out. It can be carried out and can be measured without impairing the function of the electronic device. For example, a terminal for insulation resistance measurement or an electrode for measurement of dielectric constant and dielectric loss tangent is attached to a part of the electronic control board in advance, or a pull pin is soldered for a pull test for solder strength measurement. Some test pieces are attached near the computerized control board, and the test pieces are cut out for each periodic inspection, or
Measures such as inserting an electronic control board composed only of test pieces into the device together with other electronic control boards may be considered.

The substrate material performance value thus measured is sent to the extreme value statistical processing means 4 when the measuring method and conditions comply with the standard that defines the limit value of the material performance when the remaining life is evaluated. If not, it is sent to the measured value correcting means 3. The measurement value correction means 3 compensates for the data shift that occurs between the actual measurement conditions and the measurement conditions according to the specifications of the desired standard. Specifically, the deterioration of the substrate is accelerated by an accelerated test, etc., and the data obtained by measuring the substrate material performance by both the actual measurement method and the measurement method specified by the standard are accumulated in the database 5, and the respective data are stored. The measured values are corrected based on the regression approximation function of. The extreme value statistical processing means 4 outputs the estimated extreme value to the life determining means 6 by performing the processing described in FIG. Database 5
Stores the measured value correction data and the life determination threshold value that match each other, using the diagnostic target type, standard type, substrate material performance type, etc. as keys. Further, the life diagnosis result can be stored and can be referred to as a diagnosis dictionary. The life determining unit 6 reads the estimated extreme value of the substrate material performance from the extreme value statistical processing unit 4 and the limit value (threshold value) of the substrate material performance defined in a desired standard from the database 5, and estimates the estimated extreme value. Time series change (regression approximation curve) and substrate material performance limit value (threshold value)
The remaining life and the degree of deterioration are quantitatively evaluated by the diagnostic algorithm determined by and the evaluation result is sent to the output means 7.
The output unit 7 outputs the remaining life and the degree of deterioration of the diagnosis target to the monitor, the printer, the storage device, etc. as the output of the life determination unit 6.

As described above, in the first embodiment of the electronic device life diagnosing device, the vacant space on the computerized control board is used, and the diagnostic test piece is incorporated.
The substrate material performance can be measured nondestructively without impairing the function of the target electronic device. Moreover, since the extreme value statistical processing is performed, the measurement target can be suppressed to a part of the target, and the time and effort required for diagnosis can be reduced.

FIG. 7 and FIG. 8 show a second embodiment of a life diagnostic device for an electronic device according to the present invention. In FIG. 7, the same or equivalent blocks as those in FIG. 3 are designated by the same reference numerals, and the duplicated description will be omitted. As shown in FIG. 7, the life diagnostic apparatus 10 for an electronic device according to the present embodiment is arranged between the extreme value statistical processing means 4 and the life determination means 6 to show the measured board material performance value and the state quantity of the mounted component. A state quantity calculating means (state quantity converting means) 8 for calculating the state quantity of the mounted component corresponding to the extreme value obtained by the extreme value statistical processing means 4 based on the correlation curve is connected.
In addition to the lifespan diagnosis algorithm for each diagnosis target type, the database 5 also stores a correlation curve between the board material performance and the state quantity of the mounted component.

In the electronic device life diagnosing device configured as described above, the mounted component state quantity calculating means 8 is shown in FIG.
As shown in, the measured board material performance is converted into the quantity of state of the mounted components on the board. For example, considering the insulation resistance value as the material performance of the substrate, the insulation resistance value decreases as it ages. If the decrease in the insulation resistance value is remarkable and reaches the limit value defined by the desired standard, the remaining life can be easily estimated, and the life diagnosis method may be according to the first embodiment. , Despite the deterioration over time,
When the change in the substrate material performance value is small, an index that can detect aging deterioration with high sensitivity must be used as a life diagnosis parameter. As such a parameter,
Although there are amounts of corrosion of Al wiring of IC and capacitance of electrolytic capacitor, these values cannot be measured unless the IC and electrolytic capacitor are removed from the electronic control board. Therefore, the correlation between these state quantities and the substrate material performance values that can be measured nondestructively is accelerated in advance so that the state quantities of mounted parts such as the Al wiring corrosion amount of the IC and the capacitor capacitance can be estimated nondestructively. Examined by tests, etc., and database 5
Accumulate on top. Then, the maximum value or the minimum value of the performance of the substrate material in the diagnosis target obtained by the extreme value statistical processing means 4 is determined based on the correlation and the amount of Al wiring corrosion of the IC (FIG. 8).
(A)) and the electrostatic capacity of the capacitor (FIG. 8 (c)).

The life determining means 6 checks which position on the time series curve of the state quantity the converted value corresponds to, and estimates the remaining life and the degree of deterioration (FIG. 8 (b)). , (D)). The estimated result is output to a monitor, a printer, a storage device or the like by the output means 7.

As described above, in the second embodiment of the life diagnosing apparatus for electronic devices, the A
It is possible to estimate the amount of state of mounted components such as the amount of wiring corrosion and the capacitance of a capacitor, and it is possible to quantitatively evaluate the remaining life and the degree of deterioration in a nondestructive manner without impairing the function of the electronic device. Even when the substrate material performance value does not fall outside the standard, the remaining life can be estimated by converting the substrate material performance value into a state in which the change amount is larger and the life point can be defined.

Next, FIG. 9 shows a second embodiment of the method for diagnosing the life of an electronic device according to the present invention. The method for diagnosing the life of the electronic device of the present embodiment is such that a ceramics humidity sensor for diagnosis is mounted in advance on a computerized control board that constitutes the electronic device to be diagnosed at the time of manufacturing, and the resistance change of the ceramics humidity sensor is changed. Is measured and the remaining life of the electronic control board is evaluated from the correspondence between the resistance value of the ceramic humidity sensor and the state quantity of the mounted component. The diagnostic ceramic humidity sensor is made of porous ceramic, and when water vapor enters the pores, water molecules are adsorbed on the surface of the microcrystalline particles. Generally, a ceramics humidity sensor detects humidity by utilizing physical adsorption that allows easy adsorption and desorption of water. Therefore, in order to remove chemical adsorption due to sensor deterioration and aging, ceramics are heated regularly to release water and gas that have been chemically adsorbed.However, in the present embodiment, attention is paid to chemical adsorption. , Correlation between sensor deterioration and secular change and state quantity of mounted parts is checked in advance by an acceleration test or the like and stored in a database. When the ceramic humidity sensor is chemically adsorbed with moisture or gas from the environment and deteriorates, its resistance value decreases in time series as shown in FIG. 9C. On the other hand, it has been known that moisture absorption increases the amount of Al wiring corrosion of the mounted IC, in the same way that the ceramic humidity sensor deteriorates due to chemical adsorption. Therefore, the change of the resistance value of the ceramic humidity sensor and the mounting I
If the correlation with the amount of corrosion of Al wiring of C is checked in advance and accumulated as diagnostic data in the database for each IC type, it is possible to monitor the resistance value of the ceramic humidity sensor without removing the mounted IC from the substrate. The amount of Al wiring corrosion of the mounted IC can be estimated (FIG. 9B). Then, for each IC type, the amount of corrosion leading to a failure is calculated by a high acceleration test,
The remaining life can be quantitatively evaluated by defining the resistance value of the ceramics humidity sensor when reaching this amount of corrosion as the life point. Similarly, if the correlation between the decrease in the capacitance of the mounted capacitor due to deterioration over time and the resistance value of the ceramics humidity sensor is checked in advance and accumulated as diagnostic data in the database for each capacitor type, the mounted capacitor can be removed from the board. Without measuring the resistance value of the ceramics humidity sensor, the capacitance of the mounted capacitor can be estimated, and the capacitance threshold based on the failure criterion of the capacitor is defined as the life point to quantify the remaining life. Can be evaluated. Specifically, in the time series change curve of the resistance value of the ceramics humidity sensor examined in the acceleration test,
The remaining life is calculated by performing proportional distribution calculation on three points of the resistance value of the ceramics humidity sensor, the resistance value of the ceramics humidity sensor at the time of diagnosis, and the resistance value of the ceramics humidity sensor at the life point defined by the state quantity of the mounted component. For example, as shown in FIG. 9C, the resistance value of the ceramics humidity sensor on the computerized control board taken out from the electronic device used for 10 years in the field is point b, and its initial value is point a,
If the life point resistance value is point c, the remaining life is calculated as 10 years × (bc / ac) (4). The resistance value measurement of the ceramics humidity sensor can be monitored online, but practically, as in the first embodiment, offline measurement is performed at the time of regular inspection, and extreme value statistical processing is performed to configure the diagnosis target. Estimate the minimum value of the ceramic humidity sensor resistance in all electronic control boards to be used, and estimate the remaining life from the relationship of the life point resistance value.

As described above, in the second embodiment of the method for diagnosing the life of the electronic device, the resistance value of the ceramics humidity sensor mounted in advance at the time of manufacturing is measured on the computerized control board constituting the diagnosis object. By doing so, it is possible to estimate the amount of state of mounted components such as the amount of corrosion of Al wiring of IC and the electrostatic capacity of capacitor, and to quantitatively determine the remaining life and the degree of deterioration without impairing the function of the device. Can be evaluated. Further, if a circuit for measuring the resistance value of the ceramics humidity sensor online is incorporated on the electronic control board, online life diagnosis of the electronic device becomes possible.

[0038]

As described above, according to the method of diagnosing the life of an electronic device according to the first aspect, when diagnosing the life of an electronic device including an instrument and a control device, the electronic device to be diagnosed Divide the total number of computerized control boards into multiple groups so that the number of boards in each group is approximately equal, and then extract some of the groups arbitrarily and measure the substrate material performance. In estimating the minimum or maximum of the substrate material performance value of the total substrate parameter in the diagnosis target by taking the extreme value statistics of the distribution of the substrate material performance measurement value in, the time series change of the estimated value and the substrate material Since the remaining life of the computerized control board is quantitatively evaluated from the limit value defined by the prescribed standard of performance value, the board material performance measurement value of the computerized control board is used as a parameter for life diagnosis. It is not necessary or removing a component from the electronic control board, so it can be measured by non-destructive. Since the extreme value of the board material performance value in the entire board parameter that constitutes the diagnosis target is estimated using the extreme value statistical method, it is not necessary to measure the performance value of all board parameters, and the labor and time required for diagnosis can be saved. Can be reduced. Further, since the limit value for determining the life point is defined by a predetermined standard such as JIS standard, it is not necessary to obtain the limit value by preliminary experiments, and the diagnosis can be simplified accordingly. Therefore, it is possible for a local maintenance staff to easily perform life diagnosis of the electronic device at the time of periodic inspection.

According to the second aspect of the method for diagnosing the life of the electronic device, the minimum or maximum estimated value of the substrate material performance value of the electronic control board and the electronic control board are mounted on the electronic control board. The corrosion amount of the mounted IC is calculated nondestructively from the estimated value of the substrate material performance based on the correlation curve with the corrosion amount of the IC, and the mounted IC is calculated from the time series change of the corrosion amount of the mounted IC and the correlation between the corrosion amount and the IC failure. Since the remaining life of the electronic control board is evaluated by quantitatively estimating the remaining life of the electronic control board, if the type of electronic control board and the type of mounting IC are known, the board material performance can be determined without removing the mounting IC. The corrosion progress of the mounted IC can be estimated only by non-destructive measurement, and the remaining life of the mounted IC can be quantitatively estimated from it to evaluate the remaining life of the computerized control board.

According to a third aspect of the method for diagnosing the life of an electronic device, the estimated value of the minimum or maximum value of the substrate material performance value of the computerized control board and the capacitor mounted on the computerized control board. The non-destructive determination of the performance value of the mounted capacitor from the estimated value of the substrate material performance based on the correlation curve with the performance value, and the remaining life of the mounted capacitor based on the time-series change of the mounted capacitor performance value and the failure judgment criteria of the capacitor. Since the remaining life of the computerized control board is evaluated by quantitatively estimating the value, if the type of computerized control board and the type of mounting capacitor are known, the performance of the board material can be non-destructively without removing the mounting capacitor. The progress of performance deterioration of the mounted capacitor can be estimated only by measuring, and the remaining life of the mounted capacitor can be quantitatively estimated from it to estimate the remaining life of the electronic control board. Worth can be.

According to the life diagnosing device of the electronic device of the fourth aspect, the substrate material performance measuring means for measuring the substrate material performance value of the computerized control substrate constituting the electronic device to be diagnosed, and the substrate material performance measuring And a measurement value correction means for correcting the measurement value by the substrate material performance measuring means when the measurement conditions including the structure and the pretreatment are different from the standard defining the limit value of the substrate material performance, and the correction by the measurement value correction means Extreme value statistical processing means for performing extreme value statistical processing on subsequent substrate material performance values, time-series changes of the minimum and maximum values of the substrate material performance values obtained by the extreme value statistical processing means, and the limit of the substrate material performance Life determining means for determining the remaining life from the value, correction data for performing the correction, the limit value for life determination,
Since the database for holding the extreme value statistical processing result and the determination result, and the output means for displaying a series of diagnostic results are provided, in a form different from the standard that defines the limit value of the substrate material performance at the time of measuring the substrate material performance. Even when the measurement is performed, the substrate material performance value can be corrected to the value measured under the standard, so that the remaining life can be accurately determined using the limit value defined by the predetermined standard. In addition, since the extreme value statistical processing is performed, the extreme value of the substrate material performance value in the diagnosis target can be estimated without measuring the substrate material performance value of all the boards, and the time and effort required for the diagnosis can be reduced. it can. Therefore,
A local maintenance staff can easily and accurately diagnose the life of the electronic device at the time of periodic inspection.

According to the fifth aspect of the electronic device life diagnosis apparatus of the present invention, the minimum and maximum values of the substrate material performance value obtained by the extreme value statistical processing means are used as the substrate material performance value-corrosion amount correlation for each IC type. Corrosion amount conversion means for converting into a corrosion amount of the IC mounted on the electronic control board based on a curve is provided, and the life determination means includes the conversion result of the corrosion amount by this corrosion amount conversion means and each IC type. The remaining life of the mounted IC is quantitatively evaluated based on the time-series change curve of the corrosion amount for each, and the database is various board material performance values, the board material performance value-corrosion amount correlation curve for each IC type, and the above Since the time series change curve of the corrosion amount for each IC type is stored, if the type of electronic control board and the type of mounting IC are known, the material performance of the substrate can be measured nondestructively without removing the mounting IC. Alone
The progress of corrosion of the mounted IC can be estimated using the substrate material performance value-corrosion amount correlation curve obtained from the database, and the remaining life of the mounted IC can be quantitatively evaluated from the corrosion amount leading to the IC failure. .

According to the life diagnosing device of the electronic device of the sixth aspect, the minimum and maximum values of the substrate material performance values obtained by the extreme value statistical processing means are used as the substrate material performance values for each capacitor type-
A capacitor performance conversion means for converting the performance value of the capacitor mounted on the computerized control board based on the capacitor performance correlation curve is provided, and the life determination means is the conversion result of the capacitor performance value by the capacitor performance conversion means. And the residual life of the mounted capacitors is quantitatively evaluated based on the time series change curve of the performance value for each capacitor type, and the database is various board material performance values, board material performance value for each capacitor type-capacitor performance. Since the correlation curve and the time series change curve of the performance value for each capacitor type are stored, if the type of the electronic control board and the type of the mounting capacitor are known, the mounting capacitor is not removed,
By simply measuring the board material performance non-destructively, the progress status of the performance deterioration of the mounted capacitor can be estimated using the board material performance value-capacitor performance correlation curve obtained from the database. The remaining life of the capacitor can be quantitatively evaluated.

According to a seventh aspect of the electronic device life diagnosing device, the substrate material performance measuring means comprises an insulation resistance measuring device, and measures the volume resistivity or surface resistance of a part of the computerized control substrate. Therefore, by using the insulation resistance measuring device as the substrate material performance measuring means, a local maintenance person can easily carry and measure it at the time of periodic inspection. Further, since the substrate material performance is defined as the volume resistivity or the surface resistance of a part of the electronic control board, it can be easily measured even in an electronic control board having a small space other than the mounting portion, The range of the target substrate can be expanded by changing the electrode shape flexibly.

According to another aspect of the present invention, there is provided an apparatus for diagnosing life of an electronic device, wherein the substrate material performance measuring means comprises a capacitance measuring device, and a part of the electronic control board is sandwiched by electrodes to perform the electronic conversion. Since a capacitor having a control board as a dielectric is formed and its capacitance is measured to calculate the dielectric constant of the electronic control board, it is possible to use a capacitance measuring device as the board material performance measuring means. The local maintenance staff can easily carry and measure it at the time of periodic inspection. In addition, by using the capacitance of the electronic control board as a part of the electronic control board for the substrate material performance, it is possible to easily measure even an electronic control board with a small space other than the mounting part, and a measuring device. The range of the target substrate can be expanded by changing the shape of the electrode according to circumstances.

According to a ninth aspect of the electronic device life diagnosing apparatus, the board material performance measuring means comprises a color measuring system, and the strength of the solder at the soldering portion on the computerized control board is determined by the color of the solder. Therefore, the substrate material performance value can be measured in a non-contact and non-destructive manner without impairing the function of the diagnosis target electronic device.

According to the life diagnosing device of the electronic device of the tenth aspect, according to the required standard, it is possible to measure the substrate material performance including the electrical performance and the mechanical performance by the substrate material performance measuring means. Since a test piece for measuring board material performance that has been incorporated into a part of the electronic control board in advance, the test piece for measuring board material performance is taken out at the time of on-site periodic inspection, etc. Can be done in accordance with. Thereby, the substrate material performance value can be measured without impairing the function of the electronic device.

According to the method of diagnosing the life of an electronic device according to claim 11, when diagnosing the life of an electronic device including an instrument and a control device, the electronic device control board constituting the electronic device to be diagnosed is provided. , A ceramics humidity sensor for diagnostics is mounted in advance at the time of manufacture, the resistance value change of the ceramics humidity sensor is measured, and the resistance value of the ceramics humidity sensor and the characteristic value of the mounted component mounted on the electronic control board are measured. The deterioration degree of the mounted components mounted on the electronic control board is estimated from the correspondence relationship with the electronic control board, and the remaining life of the electronic control board is evaluated. Can be detected non-destructively as a change in the resistance value of the ceramics humidity sensor, and the remaining life of the electronic control board can be evaluated from the degree of characteristic deterioration of the mounted components. Further, since the resistance value change of the ceramics humidity sensor can be monitored online, online diagnosis can be performed.

According to the method of diagnosing the life of an electronic device according to a twelfth aspect, when diagnosing the life of an electronic device including an instrument and a control device, the electronic control board constituting the electronic device to be diagnosed is provided with: A ceramics humidity sensor for diagnosis is mounted in advance at the time of manufacturing, and a change in the resistance value of the ceramics humidity sensor is measured to determine the resistance value of the ceramics humidity sensor and the corrosion amount of the IC mounted on the electronic control board. Since the corrosion amount of the mounting IC mounted on the electronic control board is estimated from the correspondence and the remaining life of the electronic control board is evaluated, the corrosion amount can be calculated without removing the mounting IC. It can be detected non-destructively as a change in the resistance value of the sensor, and the remaining life of the electronic control board can be evaluated from the corrosion amount of the mounted IC.

According to the method of diagnosing the life of an electronic device according to a thirteenth aspect, when diagnosing the life of an electronic device including an instrument and a control device, the electronic control board constituting the electronic device to be diagnosed is provided with: A ceramics humidity sensor for diagnosis is mounted in advance at the time of manufacturing, and a change in resistance value of the ceramics humidity sensor is measured, and the resistance value of the ceramics humidity sensor and the performance value of the capacitor mounted on the electronic control board are measured. The performance value of the mounting capacitor mounted on the computerized control board was estimated from the correspondence, and the remaining life of the computerized control board was evaluated. It can be detected non-destructively as a change in the resistance value of the sensor, and the remaining life of the electronic control board can be evaluated from the degree of performance deterioration of this mounted capacitor. It can be.

[Brief description of drawings]

FIG. 1 is a flowchart for explaining a first embodiment of an electronic device life diagnosis method according to the present invention.

FIG. 2 is a diagram showing a specific procedure of extreme value statistical processing in the first embodiment of the method for diagnosing the life of the electronic device.

FIG. 3 is a block diagram showing a first embodiment of an electronic device life diagnosis device according to the present invention.

FIG. 4 is a configuration diagram showing an insulation resistance measuring device which is a specific example of a substrate material performance measuring means in the first embodiment of the electronic device life diagnosing device.

FIG. 5 is a configuration diagram showing a capacitance measuring device which is a specific example of the substrate material performance measuring means in the first embodiment of the electronic device life diagnosing device.

FIG. 6 is a configuration diagram showing a color measuring system which is a specific example of the substrate material performance measuring means in the first embodiment of the electronic device life diagnosing apparatus.

FIG. 7 is a block diagram showing a second embodiment of an electronic device life diagnosis apparatus according to the present invention.

FIG. 8 is a diagram for explaining a procedure for calculating a state quantity of a state quantity calculating unit of a mounted component in the second embodiment of the life diagnostic apparatus for an electronic device.

FIG. 9 is a diagram for explaining the procedure for calculating the state quantity of the mounted component in the second embodiment of the method for diagnosing the life of the electronic device according to the present invention.

[Explanation of symbols]

1,10 Life diagnosis device for electronic devices 2 Substrate material performance measuring means 3 Measured value correction means 4 Extreme value statistical processing means 5 database 6 Life judgment means 7 Output means 8 State quantity calculation means for mounted components 11 Electronic control board 12 Insulation resistance measuring device 14 Capacitance measuring device 16 color measurement system

Continuation of the front page (56) Reference JP-A-6-11530 (JP, A) JP-A-9-304461 (JP, A) JP-A-7-249840 (JP, A) JP-A-8-86826 (JP , A) Actual development Sho 63-115771 (JP, U) Actual development 2-672 (JP, U) Saichi Keiichi, Minami Yuji, Adachi Kenji, Kumamaru Tomo, IC diagnostic method using aluminum wiring corrosion as a deterioration index , Reliability Society of Japan, Reliability, Japan, Reliability Society of Japan, November 10, 1996, November 1996, Vol. 18 / N o. 7 / Vol. 77, 75-78 (58) Fields investigated (Int.Cl. ⁷ , DB name) G01R 31/00 G01N 17/00 G01R 31/26 H01G 13/00 361

Claims (13)

(57) [Claims] 1. When diagnosing the life of an electronic device including a measuring instrument and a control device, a plurality of electronic control boards constituting the electronic device to be diagnosed are provided so that the number of electronic control boards in each group is substantially equal. In the diagnosis target by dividing the group into several groups, measuring the substrate material performance by arbitrarily extracting some groups from the divided, and taking the extreme value statistics of the distribution of the substrate material performance measurement values in each group. The minimum or maximum of the board material performance values of all board parameters is estimated, and the remaining life of the digitized control board is calculated from the time-series change of this estimated value and the limit value defined by the predetermined standard of the board material performance value. A method for diagnosing the life of an electronic device, which comprises quantitatively evaluating 2. A substrate material based on a correlation curve between an estimated minimum or maximum value of a substrate material performance value of the computerized control board and a corrosion amount of an IC mounted on the computerized control board. Non-destructively obtain the amount of corrosion of the mounted IC from the estimated value of performance,
2. The remaining life of the electronic control board is evaluated by quantitatively estimating the remaining life of the mounted IC from the time series change of the mounted IC corrosion quantity and the correlation between the corrosion quantity and the IC failure. A method for diagnosing the life of an electronic device as described. 3. A board material performance of the electronic control board based on a correlation curve between an estimated value of the minimum or maximum value of the board material performance value of the electronic control board and a performance value of a capacitor mounted on the electronic control board. The performance value of the mounted capacitor is calculated non-destructively from the estimated value, and the remaining life of the mounted capacitor is quantitatively estimated from the time-series change of the mounted capacitor performance value and the failure judgment criteria of the capacitor to estimate the remaining capacity of the electronic control board. The life diagnosis method for an electronic device according to claim 1, wherein the life is evaluated. 4. A substrate material performance measuring means for measuring a substrate material performance value of an electronic control board constituting an electronic device to be diagnosed, and a measuring condition including a structure at the time of measuring the substrate material performance and a pretreatment. Measured value correcting means for correcting the measured value by the substrate material performance measuring means when it is different from the standard defining the limit value of performance, and extreme value statistical processing is performed on the substrate material performance value after being corrected by the measured value correcting means. An extreme value statistical processing means, and a life determining means for determining the remaining life from the time-series change of the minimum and maximum values of the substrate material performance value obtained by the extreme value statistical processing means and the residual value of the substrate material performance, It has a correction data for correction, a limit value for life judgment, a database holding the extreme value statistical processing result and the judgment result, and an output means for displaying a series of diagnostic results. Life diagnosing device for electronic devices. 5. The minimum / maximum value of the substrate material performance value obtained by the extreme value statistical processing means is used as the substrate material performance value-for each IC type.
Corrosion amount conversion means for converting the corrosion amount of the IC mounted on the computerized control board based on the corrosion amount correlation curve is provided, and the life determination means includes the conversion result of the corrosion amount by the corrosion amount conversion means and The remaining life of the mounted IC is quantitatively evaluated based on the time series change curve of the corrosion amount for each IC type, and the database is various board material performance values, the board material performance value for each IC type-corrosion amount correlation. The life diagnostic device for an electronic device according to claim 4, wherein a curve and a time-series change curve of the corrosion amount for each of the IC types are accumulated. 6. The minimum and maximum values of the board material performance values obtained by the extreme value statistical processing means are mounted on the computerized control board based on a board material performance value-capacitor performance correlation curve for each capacitor type. A capacitor performance conversion means for converting to a performance value of the capacitor, the life determination means, based on the conversion result of the capacitor performance value by this capacitor performance conversion means and the time series change curve of the performance value for each capacitor type The remaining life of the mounted capacitor is quantitatively evaluated, and the database is various board material performance values, board material performance value for each capacitor type-capacitor performance correlation curve, and time series change curve of the performance value for each capacitor type. The life diagnostic device for an electronic device according to claim 4, wherein 7. The substrate material performance measuring means comprises an insulation resistance measuring device, and measures the volume resistivity or surface resistance of a part of the electronic control substrate. Life diagnostic equipment for electronic devices. 8. The substrate material performance measuring means comprises a capacitance measuring device, and a part of the electronic control board is sandwiched by electrodes to form a capacitor using the electronic control board as a dielectric. 7. The life diagnostic device for an electronic device according to claim 4, 5 or 6, wherein an electrostatic capacitance is measured to calculate a dielectric constant of the electronic control board. 9. The board material performance measuring means comprises a color measuring system, and evaluates the strength of the solder at the soldering site on the computerized control board as the color of the solder. Alternatively, the electronic device life diagnosing device according to item 6. 10. A substrate material performance measuring test piece according to a required standard is electronically controlled so that the substrate material performance including electrical and mechanical performance can be measured by the substrate material performance measuring means. The life diagnostic device for an electronic device according to any one of claims 4 to 9, wherein the life diagnostic device is incorporated in a part of a substrate in advance. 11. When diagnosing the life of an electronic device including an instrument and a control device, a ceramics humidity sensor for diagnosis is mounted in advance on a computerized control board that constitutes the electronic device to be diagnosed at the time of manufacturing. The resistance value change of the ceramic humidity sensor is measured, and the ceramic humidity sensor is mounted on the computerized control board from the correspondence relationship between the resistance value of the ceramic humidity sensor and the characteristic value of the mounting component mounted on the computerized control board. A method for diagnosing the life of an electronic device, which comprises estimating the degree of deterioration of mounted components and evaluating the remaining life of the electronic control board. 12. When diagnosing the life of an electronic device including an instrument and a control device, a ceramics humidity sensor for diagnosis is mounted in advance on a computerized control board constituting the electronic device to be diagnosed at the time of manufacturing. Then, the resistance value change of the ceramic humidity sensor is measured, and the ceramic humidity sensor is mounted on the computerized control board from the correspondence relationship between the resistance value of the ceramic humidity sensor and the corrosion amount of the IC mounted on the computerized control board. A method of diagnosing the life of an electronic device, which comprises estimating the amount of corrosion of a mounted IC and evaluating the remaining life of an electronic control board. 13. When diagnosing the life of an electronic device including an instrument and a control device, a ceramics humidity sensor for diagnosis is mounted in advance on a computerized control board constituting the electronic device to be diagnosed at the time of manufacturing. Every time, the resistance value change of this ceramic humidity sensor is measured, and it is mounted on the electronic control board from the correspondence relationship between the resistance value of the ceramic humidity sensor and the performance value of the capacitor mounted on the electronic control board. A method of diagnosing the life of an electronic device, which comprises estimating the performance value of a mounted capacitor and evaluating the remaining life of the electronic control board.