JP2018112410A - Electronic component life prediction apparatus and electronic component life prediction method - Google Patents

Abstract

The life of an electronic component is predicted in a short time. An electronic component lifetime prediction apparatus according to an embodiment includes a storage unit, a variation acquisition unit, and a lifetime calculation unit. The storage unit stores a correlation between a variation in characteristic variation in the plurality of first electronic components and a lifetime of the plurality of first electronic components after performing a composite load test that simultaneously applies a plurality of load factors. To do. The variation acquisition unit acquires the variation in the variation amount of the characteristics in the plurality of second electronic components after the combined load test is performed. The lifetime calculation unit calculates the lifetimes of the plurality of second electronic components based on the correlation stored in the storage unit and the obtained variation in the variation amount of the characteristic. [Selection] Figure 1

Description

  Embodiments described herein relate generally to an electronic component lifetime prediction apparatus and an electronic component lifetime prediction method.

  It is known that various characteristics such as capacitance of electronic parts such as electrolytic capacitors and LEDs deteriorate over time. Therefore, a technique for predicting the lifetime (lifetime) of an electronic component in a short time has been proposed.

  When predicting the lifetime of an electronic component, the service life and the like are verified by performing an accelerated deterioration test on the electronic component, for example. In general, when an accelerated deterioration test is performed in consideration of the warranty period and standards of an electronic component, it is important to predict the lifetime of the electronic component in an actual usage environment.

JP 2013-44714 A JP 2012-13882 A2

  In recent years, it is necessary to perform accelerated deterioration tests ranging from several thousand hours to several tens of thousands of hours as the life of electronic components is extended (longer service life). For this reason, in recent electronic parts, it takes much time to predict the service life. That is, in order to shorten the development period of electronic devices on which electronic components are mounted, it is required to reduce the time required for predicting the lifetime of electronic components.

  Therefore, the problem to be solved by the present invention is to provide an electronic component lifetime predicting apparatus and an electronic component lifetime predicting method capable of predicting the lifetime of an electronic component in a short time.

  An electronic component lifetime prediction apparatus according to an embodiment includes a storage unit, a variation acquisition unit, and a lifetime calculation unit. The storage unit stores a correlation between a variation in characteristic variation in the plurality of first electronic components and a lifetime of the plurality of first electronic components after performing a composite load test that simultaneously applies a plurality of load factors. To do. The variation acquisition unit acquires the variation in the variation amount of the characteristics in the plurality of second electronic components after the combined load test is performed. The lifetime calculation unit calculates the lifetimes of the plurality of second electronic components based on the correlation stored in the storage unit and the obtained variation in the variation amount of the characteristic.

  ADVANTAGE OF THE INVENTION According to this invention, the lifetime prediction apparatus of an electronic component and the lifetime prediction method of an electronic component which can estimate the lifetime of an electronic component in a short time can be provided.

The block diagram which shows functionally the structure of the lifetime prediction apparatus of the electronic component which concerns on embodiment. Sectional drawing of the electrolytic capacitor which the lifetime prediction apparatus of FIG. The figure which illustrated the result of the temperature acceleration deterioration test as a comparative example. The flowchart for obtaining the correlation approximate line which the lifetime prediction apparatus of FIG. 1 applies. The figure which shows an example of the correlation approximated line of FIG. The flowchart for selecting the load factor of the compound load test which the lifetime prediction apparatus of FIG. 1 uses. The figure which shows an example of the test conditions for every load factor applicable to the electrolytic capacitor of FIG. The figure which illustrated the usefulness at the time of combining with the influence degree with respect to the fall of the electrostatic capacitance for every load factor applicable to the electrolytic capacitor of FIG. 2, and another load factor. The graph which shows an example of the influence degree with respect to the fall of the electrostatic capacitance of the single load factor applicable to the electrolytic capacitor of FIG. The graph which shows an example of the influence degree with respect to the fall of the electrostatic capacitance of the composite load factor applicable to the electrolytic capacitor of FIG. The figure which shows an example of the test conditions for every load factor applicable to LED. The flowchart which estimates the lifetime of the electronic component by the lifetime prediction apparatus of FIG.

Hereinafter, embodiments will be described with reference to the drawings.
As shown in FIG. 1, the electronic component lifetime prediction apparatus 10 according to the present embodiment includes a correlation storage unit 11, a variation acquisition unit 12, a lifetime calculation unit 13, a database 14, an influence degree determination unit 15, and the like. .

  The correlation storage unit 11 includes a variation in characteristic variation (functional margin SN ratio) in the plurality of first electronic components after performing the composite load test, and a lifetime of the plurality of first electronic components. The correlation (correlation approximate line) is stored. In the composite load test, a plurality of load factors are simultaneously applied to an electronic component to be tested. On the other hand, the variation obtaining unit 12 obtains variation in characteristic variation in the plurality of second electronic components after the combined load test is performed. Here, each of the plurality of first and second electronic components described above is an electronic component having a common product specification, and more specifically, although the manufacturer and the manufacturing location are different, Electronic parts with the same specifications (product standards).

  The lifetime calculation unit 13 calculates the lifetimes of the plurality of second electronic components based on the correlation stored in the correlation storage unit 11 and the variation in the amount of variation in characteristics acquired by the variation acquisition unit 12. calculate. The database 14 stores various data necessary for predicting the lifetime of the electronic component. The influence degree determination unit 15 determines the influence degree of a single load factor (for each load factor) on the temporal deterioration of the first and second electronic components in order to select a load factor to be applied to the composite load test. To do. The configuration of each unit shown in FIG. 1, such as the correlation storage unit 11, the variation acquisition unit 12, and the life calculation unit 13, will be described in detail later.

  As shown in FIG. 2, in the present embodiment, a lead-type electrolytic capacitor 20 is exemplified as the first and second electronic components applied to the life prediction. The electrolytic capacitor 20 is a finite-life component that is frequently used in industrial equipment for smoothing a power supply circuit. The electrolytic capacitor 20 includes a sleeve 21, an aluminum case 22, an element portion 23, a sealing rubber 24, an aluminum lead 25, and a lead wire 26. When the electrolytic capacitor is a surface mount type, the lead wire has a shape different from that shown in FIG.

  As shown in FIG. 2, the element part 23 has an anode foil in which the surface area of the aluminum foil is increased by etching, the surface area is enlarged, and a thin oxide film having a high withstand voltage is formed by chemical conversion, and a cathode only with etching. It is manufactured by inserting electrolytic paper between the foil and winding it on a cylindrical element. Further, the element portion 23 is impregnated with an electrolytic solution, the element portion 23 is put in the aluminum case 22, and then packed with a sealing rubber 24, and the aluminum case 22 is subjected to drawing processing to be sealed. Thereafter, the outer surface of the aluminum case 22 is covered with a sleeve 21 on which necessary indications such as a rated value are given.

  In the electrolytic capacitor 20 having such a structure, the electrolytic solution impregnated therein flows out from the periphery of the sealing rubber 24 to the outside due to deterioration over time, and the capacitance represents a capacitance and a dielectric representing the degree of electric energy loss in the dielectric. Various characteristics such as tangent (tan δ) and leakage current are deteriorated. Here, FIG. 3 exemplifies the result of an accelerated deterioration test (temperature accelerated deterioration test) in which the temperature element is applied as a single load factor to two types of electrolytic capacitors of different varieties. Assuming that the change rate of the capacitance is, for example, −7% to −10%, as reaching the product life, in FIG. 3, the evaluation time (life prediction time) extending from several thousand hours to tens of thousands of hours. ) Is necessary.

  Therefore, as described above, the electronic component lifetime prediction apparatus 10 according to the present embodiment has a function capable of predicting the lifetime of an electronic component such as an electrolytic capacitor that deteriorates over time in a short time. Yes. First, with reference to FIGS. 4 to 6, a procedure for obtaining a correlation approximation line necessary for predicting the lifetime will be described.

  As shown in FIG. 4, a plurality of types of electrolytic capacitors (the above-described first electronic components) are prepared one by one (S [Step] 1). As the electrolytic capacitor to be prepared, for example, it is not necessary to specifically limit the model or dimensions, but a capacitor having a common product specification is prepared. For example, three to five types of electrolytic capacitors of three or more types are prepared.

  Next, for example, capacitance is measured as an initial characteristic for each electrolytic capacitor (S2). The initial characteristic is the characteristic before the composite load test is performed. In addition, although the electrostatic capacitance is illustrated as an example of the characteristic of the electrolytic capacitor, it is not necessary to limit the characteristic to be measured to the electrostatic capacity. When there are a plurality of characteristics to be degraded, at least one of the characteristics to be deteriorated may be measured to measure the initial characteristics of the designated characteristics. The measurement environment is, for example, an environment of normal temperature and normal humidity.

  Subsequently, a composite load test is performed on each electrolytic capacitor whose initial characteristics are measured (S3). In the composite load test, a plurality of types of load factors (elements causing deterioration) are simultaneously applied to the electrolytic capacitor. This combined load test is about several tens of hours shorter than the accelerated deterioration test (the above-mentioned temperature accelerated deterioration test that required several thousand hours or more of test time) in which the temperature factor is applied as a single load factor. Complete in test time.

  Next, after the composite load test is completed, the capacitance is measured as various characteristics of each electrolytic capacitor (S4). The measurement environment in this case is also an environment of room temperature and normal humidity, for example, as in S2 (step 2). Next, the function margin SN ratio is calculated based on the characteristics measured before the composite load test and the characteristics measured after the composite load test for each electrolytic capacitor (S5). That is, the function margin SN ratio indicating the variation in the variation (capacitance) of the characteristics of each electrolytic capacitor before and after the composite load test is obtained.

The function margin SN ratio can be calculated, for example, as a desired characteristic of the static characteristics in quality engineering, and the larger the SN ratio, the smaller the variation of the characteristic variation amount (capacitance). It is known that the S / N ratio of such a static characteristic is calculated using the following Equation 1. Here, “y _i0 ” in Equation 1 is the initial characteristic, “y _i ” is the characteristic after the load test, and “n” is the number of samples.

  Finally, as shown in FIG. 4 and FIG. 5, the correlation between the calculated function margin SN ratio (variation in the amount of variation in the characteristics of each electrolytic capacitor) and the lifetime of the electrolytic capacitor (first electronic component). A correlation approximate line representing the relationship is generated with reference to the contents of the database 14 (S6). The correlation storage unit 11 stores the generated correlation approximate line.

  The database 14 stores, for example, information related to other electrolytic capacitors (other electronic components whose lifetimes have been verified) having different types from the electrolytic capacitors prepared in S1 (step 1). However, other electrolytic capacitors (other electronic components) having different types are electronic components having, for example, common specifications or similar specifications to the prepared electrolytic capacitors. In the database 14, for example, the relationship between the life of the electrolytic capacitors of different types and the function margin SN ratio is stored in advance. Therefore, the correlation approximation line shown in FIG. 5 can be obtained based on the function margin SN ratio calculated in S1 (step 5) and the stored contents of the database 14.

  Next, a processing procedure for selecting a load factor to be applied to the composite load test of S3 (step 3) shown in FIG. 4 will be described with reference to FIGS. As in step S1 shown in FIG. 4, first, as shown in FIG. 6, a plurality of types of electrolytic capacitors (the first electronic components described above) are prepared one by one (S11). Next, as in step S2 shown in FIG. 4, initial characteristics of the plurality of electrolytic capacitors are measured (S12).

  Furthermore, as shown in FIG. 7, load factors that affect the characteristics of the measurement target are listed. For each of the listed load factors, a single load test condition is formulated based on the limit points and standard values. In the composite load test, a load factor within a condition range (below the above-mentioned limit point) capable of maintaining the physical properties of the constituent materials in the electrolytic capacitor (the first and second electronic components described above) is applied. Under the above-defined single load test conditions, for example, a single load test is performed in which a load corresponding to each load factor is applied to the electrolytic capacitor for several tens of hours (S13). The single load test may be performed on a plurality of electrolytic capacitors or a single electrolytic capacitor.

  Next, after the single load test is completed, the capacitance is measured as various characteristics of each electrolytic capacitor (S14). Note that the measurement environment is, for example, an environment of normal temperature and normal humidity, similar to S2 (step 2). Next, the functional margin SN ratio is calculated based on the characteristics measured before the single load test and the characteristics measured after the single load test for each electrolytic capacitor (S15). That is, the function margin SN ratio indicating the variation in the variation (capacitance) of the characteristics of each electrolytic capacitor before and after the single load test is obtained. In this case, the function margin SN ratio is also calculated, for example, by using the above-described equation 1 to calculate the SN ratio of the static characteristic in quality engineering (the SN ratio of the small desired characteristic).

  Finally, based on the function margin SN ratio calculated in S15 (step 15), the influence determination unit 15 determines the influence of each load factor on the electrolytic capacitor (S16). That is, the influence degree determination unit 15 uses the load factor to be applied in the composite load test as the amount of characteristic variation in the plurality of electrolytic capacitors (first electronic components) after performing a single load test that gives one load factor. Select based on variation in By determining the degree of influence, an appropriate load factor to be applied in combination in the composite load test in S3 (step 3) shown in FIG. 4 is selected.

  FIG. 7 shows an example in which test condition proposals are formulated with reference to, for example, the limit points of constituent materials of electrolytic capacitors and standard values. Possible failure mechanisms that decrease the capacitance of the electrolytic capacitor include dry-up of the electrolyte, formation of a dielectric oxide film, and hydration. For this reason, for example, temperature, humidity (for example, 80% of humidity is continued for 50 hours), heat cycle, reverse voltage (for example, applying -1.5V to -2V), overvoltage (for example, applying 1.5 times the rated voltage) Are listed as load indicators (extraction factors).

  In the combined load test, conditions for applying the load factor are appropriately selected for each electronic component from the environmental load factor and the electrical load factor. FIG. 8 shows the usefulness of the degree of influence for each load factor on the characteristics (capacitance) of the electrolytic capacitor and combinations with other load factors for each load factor. Here, “◎” is large, “◯” is slightly large, “△” is slightly small, and “×” is small for each item (influence, usefulness of combination) in FIG. Show.

  Moreover, FIG. 9 has illustrated the calculation result of the function margin SN ratio (for every load factor) at the time of implementing a single load test. FIG. 9 shows functional margin SN ratios calculated by giving load factors of temperature, humidity and reverse voltage to two types of electrolytic capacitors (components A and B). Based on this result shown in FIG. 9, the influence determination unit 15 selects a plurality of load factors to be applied in the composite load test. For example, the plurality of load factors to be selected are selected from environmental load factors or electrical load factors. In FIG. 9, when the load factor is a reverse voltage, the function margin SN ratio is smaller than when the load factor is humidity, and thus the degree of influence on the decrease in the capacitance of the electrolytic capacitor is large. . For example, the reverse voltage is suitable for a combination with temperature and can be applied simultaneously. For this reason, it is preferable to select temperature and reverse voltage as load factors to be applied simultaneously in the composite load test.

  FIG. 10 is an example of a result of performing a combined load test. As shown in FIG. 10, the composite load test that gives temperature and reverse voltage as load factors has a smaller function margin SN ratio (gain) than the reliability test with the rated voltage and rated temperature as test conditions. From this, it can be determined that it is suitable for obtaining the correlation approximation line shown in FIG. 5 because it greatly affects the decrease in the capacitance of the electrolytic capacitor.

  FIG. 11 is an example of test conditions regarding each load factor for a light emitting diode (LED). It is assumed that the load factor selected for the electrolytic capacitor is different from the load factor selected for the light emitting diode. In addition to the load factor selected for the electrolytic capacitor, the load factor selected for the light emitting diode further includes vibration, corrosive gas, light and the like as shown in FIG.

  Next, a procedure for predicting the lifetime of the electrolytic capacitor (second electronic component) will be described with reference to FIG. As shown in FIG. 12, a plurality of types of electrolytic capacitors (second electronic components described above) to be subjected to life prediction are prepared (S21). For the electrolytic capacitor to be prepared, for example, although it is not necessary to limit the model and dimensions, those having common product specifications are prepared. For example, three to five types of electrolytic capacitors of three or more types are prepared.

  Next, in the measurement environment of normal temperature and normal humidity where S2 (step 2) is performed, the capacitance is measured as an initial characteristic for each electrolytic capacitor (S22). The measurement environment in this case is also an environment of room temperature and normal humidity, for example, as in S2 (step 2). The initial characteristic is the characteristic before the composite load test is performed. Next, a composite load test is performed on each electrolytic capacitor whose initial characteristics are measured (S23). In this case, the combined load test is performed under the same test conditions as S3 (step 3) shown in FIG.

  Subsequently, after the composite load test is completed, the characteristics (capacitance) of each electrolytic capacitor are measured (S24). The measurement environment in this case is also an environment of room temperature and normal humidity, for example, as in S2 (step 2). Next, the function margin SN ratio is calculated based on the characteristics measured before the composite load test and the characteristics measured after the composite load test for each electrolytic capacitor (S25). That is, the variation acquisition unit 12 acquires a function margin SN ratio that represents variations in the amount of variation (capacitance) of the characteristics of each electrolytic capacitor (second electronic component) before and after the composite load test.

  Finally, the life calculation unit 13 is based on the correlation approximation line (correlation) shown in FIG. 5 stored in the correlation storage unit 11 and the function margin SN ratio acquired by the variation acquisition unit 12. The lifetimes of a plurality of electrolytic capacitors (second electronic components) are calculated.

  As described above, in the electronic component life prediction apparatus 10 and the electronic component life prediction method according to the present embodiment, the composite load test that simultaneously gives a plurality of load factors and the function margin SN ratio in quality engineering are effectively obtained. By applying it, the lifetime of the electronic component can be predicted with high accuracy in a short time.

  As mentioned above, although embodiment of this invention was described, this embodiment is shown as an example and is not intending limiting the range of invention. The novel embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 ... Life prediction apparatus of an electronic component, 11 ... Correlation memory | storage part, 12 ... Variation acquisition part, 13 ... Life calculation part, 20 ... Electrolytic capacitor.

Claims (12)

A storage unit for storing a correlation between a variation in characteristic variation in the plurality of first electronic components and a lifetime of the plurality of first electronic components after performing a composite load test for simultaneously applying a plurality of load factors; ,
A variation acquisition unit that acquires variations in the amount of variation in characteristics in the plurality of second electronic components after performing the composite load test;
A lifetime calculating unit that calculates the lifetimes of the plurality of second electronic components based on the correlation stored in the storage unit and the variation in the amount of variation in the acquired characteristics;
A device for predicting the life of electronic components. Each of the plurality of first and second electronic components is an electronic component having a common product specification.
The lifetime prediction apparatus of the electronic component of Claim 1. The load factor to be applied in the composite load test is selected based on variation in the amount of variation in characteristics of the plurality of first electronic components after performing a single load test that gives one load factor.
The lifetime prediction apparatus of the electronic component of Claim 1 or 2. In the composite load test, a load factor within a condition range in which the physical properties of the constituent materials in the first and second electronic components can be maintained is applied.
The lifetime prediction apparatus of the electronic component of any one of Claim 1 to 3. The combined load test is completed in a shorter test time than an accelerated degradation test in which the temperature factor is applied as a single load factor.
The lifetime prediction apparatus of the electronic component of any one of Claim 1 to 4. The variation in the variation amount of the characteristics in the plurality of first and second electronic components is a function margin SN ratio that can be calculated as a desired characteristic of the static characteristics in quality engineering.
The lifetime prediction apparatus of the electronic component of any one of Claim 1-5. The storage unit stores the correlation between the variation in the characteristic variation in the plurality of first electronic components and the lifetime of the plurality of first electronic components after performing the composite load test that simultaneously gives a plurality of load factors. Steps,
Obtaining a variation in the amount of variation in characteristics in the plurality of second electronic components after performing the composite load test;
Calculating the lifetime of the plurality of second electronic components based on the correlation stored in the storage unit and the variation in the amount of variation in the acquired characteristics;
A method for predicting the lifetime of electronic parts having Each of the plurality of first and second electronic components is an electronic component having a common product specification.
The method for predicting the lifetime of an electronic component according to claim 7. Selecting a load factor to be applied in the composite load test on the basis of variations in the amount of variation in characteristics of the plurality of first electronic components after performing a single load test that provides one load factor;
The method for predicting the lifetime of an electronic component according to claim 7 or 8, further comprising: In the composite load test, a load factor within a condition range in which the physical properties of the constituent materials in the first and second electronic components can be maintained is applied.
The method for predicting the lifetime of an electronic component according to any one of claims 7 to 9. The combined load test is completed in a shorter test time than an accelerated degradation test in which the temperature factor is applied as a single load factor.
The lifetime prediction method of the electronic component of any one of Claim 7-10. The variation in the variation amount of the characteristics in the plurality of first and second electronic components is a function margin SN ratio that can be calculated as a desired characteristic of the static characteristics in quality engineering.
The method for predicting the lifetime of an electronic component according to any one of claims 7 to 11.

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