JP7445884B2 - Inspection methods, management methods, production methods, and inspection systems - Google Patents

Description

The present disclosure generally relates to an inspection method, a management method, a production method, and an inspection system, and more particularly relates to a capacitor inspection method, management method, production method, and inspection system.

Patent Document 1 describes a method for processing capacitor elements.

The capacitor element includes an anode foil to which an anode lead is connected, a cathode foil to which a cathode lead is connected, and a separator interposed between the cathode foil and the anode foil. In this processing method, a low-voltage pulse current is first applied between the anode side lead and the cathode side lead of the capacitor element to cut the short circuit caused by the protrusion of the anode foil and the cathode foil. Next, a high-voltage pulse current is applied between the anode side lead and the cathode side lead to widen the proximal portion of the anode foil and cathode foil at the cut portion of the short circuit.

Japanese Patent Application Publication No. 10-256104

In the processing method described in Patent Document 1, a pulse current is uniformly applied to a capacitor element to perform processing. Therefore, the processing method described in Patent Document 1 has a problem in that it is difficult to manage the condition of the target capacitor element, such as whether or not there is actually a protrusion on the anode foil or the cathode foil.

The present disclosure has been made in view of the above reasons, and aims to provide an inspection method, a management method, a production method, and an inspection system that make it easy to manage the state of a target capacitor element.

A testing method according to one aspect of the present disclosure is a testing method for a capacitor element used in a capacitor. The capacitor element has a pair of electrodes. The inspection method includes a voltage application step and a measurement step. The voltage application step includes applying an applied voltage that increases over time between the pair of electrodes until a discharge occurs between the pair of electrodes. The measuring step includes measuring, as a discharge voltage, the applied voltage when the discharge occurs between the pair of electrodes in the voltage application step. The voltage application step includes controlling the rate of increase in the applied voltage by flowing a current from a constant current source to the pair of electrodes via a switching element whose switching is controlled.
A testing method according to one aspect of the present disclosure is a testing method for a capacitor element used in a capacitor. The capacitor element has a pair of electrodes. The inspection method includes a voltage application step and a measurement step. The voltage application step includes applying an applied voltage that increases over time between the pair of electrodes until a discharge occurs between the pair of electrodes. The measuring step includes measuring, as a discharge voltage, the applied voltage when the discharge occurs between the pair of electrodes in the voltage application step. In the voltage application step, the applied voltage is increased from an initial voltage over time. The initial voltage is greater than 0V.

A management method according to one aspect of the present disclosure is a management method for capacitors manufactured by a capacitor manufacturing system. The management method includes an inspection step. The testing step includes performing the testing method on a plurality of the capacitor elements.

A production method according to one aspect of the present disclosure is a capacitor production method using the inspection method or the management method.

An inspection system according to one aspect of the present disclosure is an inspection system for a capacitor element used in a capacitor. The capacitor element has a pair of electrodes. The inspection system includes a voltage application section and a measurement section. The voltage application section applies an applied voltage that increases over time between the pair of electrodes until discharge occurs between the pair of electrodes. The measurement unit measures the applied voltage when discharge occurs between the pair of electrodes as a discharge voltage. The voltage application section controls the rate of increase in the applied voltage by causing current to flow from a constant current source to the pair of electrodes via a switching element whose switching is controlled.
An inspection system according to one aspect of the present disclosure is an inspection system for a capacitor element used in a capacitor. The capacitor element has a pair of electrodes. The inspection system includes a voltage application section and a measurement section. The voltage application section applies an applied voltage that increases over time between the pair of electrodes until discharge occurs between the pair of electrodes. The measurement unit measures the applied voltage when discharge occurs between the pair of electrodes as a discharge voltage. The voltage application unit increases the applied voltage from an initial voltage over time. The initial voltage is greater than 0V.

According to the present disclosure, there is an advantage that it is possible to provide an inspection method, a management method, a production method, and an inspection system that make it easy to manage the state of a target capacitor element.

FIG. 1 is a flowchart showing the operation of an inspection system according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional view of a main part of a capacitor element that is an object of inspection by the above inspection system. FIG. 3 is a perspective view of a capacitor including the same capacitor element as above. FIG. 4 is a partial cross-sectional view of the same capacitor as seen from an angle. FIG. 5 is a sectional view of the same capacitor as above. FIG. 6 is a block diagram of a system including a capacitor manufacturing system, an inspection system, and a management system for manufacturing the same capacitor as described above. FIG. 7 is a flowchart showing a method for manufacturing a capacitor. FIG. 8 is a schematic diagram of a model device used to study the above inspection system. FIG. 9 is a schematic diagram of a voltage application device used in the examination of the above inspection system. FIG. 10 is an explanatory diagram showing changes in the output voltage of the voltage application device in the study of the above inspection system. FIG. 11 is an explanatory diagram showing the relationship between the discharge voltage and the distance between the electrodes, which was obtained by examining the above inspection system. FIG. 12 is an explanatory diagram showing the relationship between the discharge voltage and the rate of increase in voltage, which was obtained by examining the above inspection system. FIG. 13A and FIG. 13B are explanatory diagrams showing the distribution of discharge voltage obtained by examining the above inspection system. FIG. 14 is a schematic diagram of a voltage application device used in the examination of the above inspection system. FIG. 15 is a block diagram of the same inspection system as above. FIG. 16 is an explanatory diagram showing changes over time in the applied voltage of the above inspection system. FIG. 17 is a flowchart showing the operation of the inspection system according to a modified example.

(1) Overview Each figure described in the following embodiments is a schematic diagram, and the ratio of the size and thickness of each component in each figure does not necessarily reflect the actual size ratio. Not necessarily.

The testing method according to this embodiment is, for example, a testing method for a capacitor element 10 used in a capacitor 1 shown in FIG. 4. Capacitor element 10 has an anode 101 and a cathode 102 as a pair of electrodes. The anode 101 includes an anode foil 11 and an anode lead terminal 14 . The cathode 102 includes a cathode foil 12 and a cathode lead terminal 15. Anode lead terminal 14 is connected to anode foil 11. Cathode lead terminal 15 is connected to cathode foil 12 . Further, the capacitor element 10 further includes a separator 13. The separator 13 is interposed between the anode foil 11 and the cathode foil 12 to prevent the anode foil 11 and the cathode foil 12 from coming into contact with each other.

As shown in FIG. 1, the inspection method of this embodiment includes a voltage application step ST1 and a measurement step ST2.

The voltage application step ST1 includes applying an applied voltage V0 that increases over time between the pair of electrodes 101 and 102 until discharge occurs between the pair of electrodes 101 and 102.

The measurement step ST2 includes measuring the applied voltage V0 when a discharge occurs between the pair of electrodes 101 and 102 in the voltage application step ST1 as the discharge voltage Vsp.

Generally, the withstand voltage (withstanding voltage) of the capacitor 1 is determined depending on the shortest distance between the anode 101 and the cathode 102. Therefore, as shown in FIG. 2, for example, there may be conductive protrusions such as burrs 91 on the anode foil 11 or the cathode foil 12, or there may be conductive foreign matter 92 between the anode foil 11 and the cathode foil 12. If this occurs, the withstand voltage of the capacitor 1 may decrease. Therefore, as in the technique described in Patent Document 1, for example, in the manufacturing stage of a capacitor element, a process is sometimes performed to remove burrs and foreign substances by passing a current between a pair of electrodes in advance. However, simply passing a uniform pulse current through a capacitor element as in the technique described in Patent Document 1 does not allow for the investigation of whether or not there is actually a burr or foreign matter on the target to be processed. It is difficult to manage the state of the capacitor element.

On the other hand, in the inspection method of this embodiment, the discharge voltage Vsp is measured as described above. As will be described later, the discharge voltage Vsp depends on the distance (shortest distance) between the electrodes 101 and 102. Further, if the burr 91 or the foreign object 92 exists, the substantial distance between the electrodes 101 and 102 becomes smaller by the size thereof. Therefore, by measuring the discharge voltage Vsp for each capacitor element 10, the state of the capacitor element 10 can be ascertained, such as whether a burr 91 or foreign matter 92 was present in the capacitor element 10 before applying the applied voltage V0. It becomes easier. Therefore, the testing method of this embodiment has the advantage that the state of the capacitor element 10 to be tested can be easily managed.

Furthermore, the management method of this embodiment is a method of managing capacitors 1 manufactured by capacitor manufacturing system 100, and includes performing the above-described inspection method on a plurality of capacitor elements 10.

In this way, by performing the inspection method of this embodiment on a plurality of capacitor elements 10, it becomes possible to understand changes in the manufacturing conditions of the capacitor elements 10. For example, it is assumed that the average value of the discharge voltage Vsp is smaller in the plurality of capacitor elements 10 manufactured on a different day after that than in the plurality of capacitor elements 10 manufactured on a certain day. In this case, it may be suspected that the discharge voltage Vsp has decreased due to an increase in the number of burrs 91 or foreign substances 92. Therefore, the user of the capacitor manufacturing system 100 can suspect, for example, the possibility of aging deterioration of the capacitor manufacturing system 100 or the possibility of a change in the surrounding environment of the capacitor manufacturing system 100. Therefore, the management method of this embodiment has the advantage that the state of the capacitor manufacturing system 100 can be easily managed.

(2) Details Below, the inspection method, management method, production method, and inspection system of this embodiment will be described in more detail with reference to FIGS. 1 to 16.

(2.1) Capacitor First, the capacitor 1 including the capacitor element 10, which is the test target of the test method of this embodiment, will be described with reference to FIGS. 3 to 5.

The capacitor 1 is a surface-mount type or lead type electrolytic capacitor here, and may also be an electrolytic capacitor using a conductive polymer or an electrolytic solution as an electrolyte, or an electrolytic capacitor that uses a conductive polymer and an electrolytic solution as an electrolyte. It may also be a so-called hybrid type electrolytic capacitor. Among these, the capacitor 1 is preferably a hybrid type electrolytic capacitor that is used in vehicles and requires high reliability. When a conductive polymer is used, a drop in discharge voltage is likely to occur due to burrs or foreign matter, and the effect of the inspection method of this embodiment can be further enhanced.

FIG. 3 is a perspective view of the surface mount type capacitor 1. FIG. 4 is a partial cross-sectional view of the capacitor 1 viewed from an angle. FIG. 5 is a cross-sectional view of the capacitor 1.

As shown in FIG. 4, the capacitor 1 includes a capacitor element (winding element) 10, a case (exterior) 20, a sealing member 30, an electrolyte 40, and a seat plate 50. As described above, the capacitor element 10 includes the anode 101 (the anode foil 11 and the anode lead terminal 14), the cathode 102 (the cathode foil 12 and the cathode lead terminal 15), and the separator 13.

The anode foil 11 includes, for example, a metal foil whose surface has been roughened by etching or the like. The metal foil is, for example, aluminum foil. The material of the metal foil is preferably a metal with valve action such as aluminum, tantalum, niobium, or an alloy thereof. A dielectric film (dielectric layer) 16 is formed on the surface of the metal foil. The dielectric film 16 is formed, for example, by chemically treating metal foil. The chemical conversion treatment is performed, for example, by immersing the metal foil in a chemical solution and applying heat and voltage as necessary.

The cathode foil 12 includes, for example, metal foil. The metal foil is, for example, aluminum foil. The material of the metal foil is preferably a metal with valve action such as aluminum, tantalum, niobium, or an alloy thereof. The metal foil of the cathode foil 12 may be subjected to surface roughening treatment and/or chemical conversion treatment, if necessary. The surface of the metal foil of the cathode foil 12 may be covered with a carbon film, a titanium film, or the like.

Separator 13 is arranged between anode foil 11 and cathode foil 12 to prevent contact between anode foil 11 and cathode foil 12. The capacitor element 10 includes a pair of separators 13. Separator 13 is formed of a material having electrical insulation properties. The separator 13 is not particularly limited, and may be, for example, insulating paper or a nonwoven fabric whose main component is cellulose, polyethylene terephthalate, vinylon, polyamide, glass, or the like.

Anode lead terminal 14 is connected to anode foil 11. The material of the anode lead terminal 14 is not particularly limited, and may be any conductive material. The anode lead terminal 14 integrally includes a lead tab 141 and a terminal plate 142. Lead tab 141 is connected to anode foil 11 inside case 20 . The terminal plate 142 is exposed to the outside of the case 20.

Cathode lead terminal 15 is connected to cathode foil 12 . The material of the cathode lead terminal 15 is not particularly limited, and may be any conductive material. The cathode lead terminal 15 integrally includes a lead tab 151 and a terminal plate 152. Lead tab 151 is connected to cathode foil 12 inside case 20 . The terminal plate 152 is exposed to the outside of the case 20.

For example, the anode foil 11 to which the anode lead terminal 14 is connected, one of the pair of separators 13, the cathode foil 12 to which the cathode lead terminal 15 is connected, and the other of the pair of separators 13 are stacked in this order. Then, the anode foil 11, the cathode foil 12, and the pair of separators 13 are wound up into a roll, so that the capacitor element (rolled element) 10 is formed into a cylindrical shape.

The case 20 is made of a material such as aluminum and has a cylindrical shape with an open bottom. The capacitor element 10 is housed in the case 20 so that the terminal plate 142 of the anode lead terminal 14 and the terminal plate 152 of the cathode lead terminal 15 are exposed to the outside.

In the capacitor 1, a conductive polymer is disposed within the case 20 between the anode foil 11 and the cathode foil 12. The conductive polymer material may be, for example, polypyrrole, polythiophene, polyaniline, derivatives thereof, etc., and a dopant may also be added. The conductive polymer is, for example, on at least a portion of at least one of the surface of the dielectric film 16 formed on the surface of the metal foil of the anode foil 11, the surface of the cathode foil 12, and the surface of the separator 13. It may be attached in the form of a film. Furthermore, an electrolytic solution (electrolyte 40) is injected into the case 20 after the capacitor element 10 is housed therein.

The sealing member 30 is made of an elastic material such as rubber. The sealing member 30 is attached to the case 20 so as to close the opening on the lower surface of the case 20. Two through holes are formed in the sealing member 30.

The seat plate 50 is made of an electrically insulating material. The seat plate 50 is attached to the lower part of the case 20. Two through holes are formed in the seat plate 50 at positions corresponding to the two through holes of the sealing member 30, respectively. Furthermore, two accommodation recesses are formed on the bottom surface (lower surface) of the seat plate 50, extending outward from the exit of each through hole.

The anode lead terminal 14 and the cathode lead terminal 15 protruding from the inside of the case 20 to the outside are passed through the through hole of the sealing member 30 and the through hole of the seat plate 50, and are bent outward. The outwardly bent portion of the anode lead terminal 14 is accommodated in one of the two accommodation recesses of the seat plate 50 as the terminal plate 142. The outwardly bent portion of the cathode lead terminal 15 is accommodated in the other of the two accommodation recesses of the seat plate 50 as a terminal plate 152 .

As shown in FIG. 3, a display section 60 showing the characteristics of the capacitor 1 is provided on the top surface 21 of the case 20. The display section 60 is displayed on the top surface 21 of the case 20 by printing. Note that in FIG. 4, illustration of the display unit 60 is omitted. The display contents of the display unit 60 include, for example, a black polarity display indicating the polarity (-pole side) of the capacitor 1, a capacitance value (numerical value: unit is μF), a rated voltage symbol, and a series symbol. , a lead-free product mark (black dot), and a lot number (a number indicating the production lot). In the capacitor 1 of this embodiment, a polarity indicator is attached to the first region (left side in FIG. 3) of the top surface 21 of the case 20. In addition, in the second area of the top surface 21 of the case 20 (on the right side of FIG. 3), capacitance is attached to the upper row, a rated voltage symbol and a series symbol are attached to the middle row, and a lot number is attached to the lower row. There is. Of course, the display contents, numerical values, etc. on the display unit 60 are not limited to those shown in FIG. 3.

Further, as shown in FIG. 3, the case (exterior) 20 is provided with an identifier 70 in addition to the display section 60. The identifier 70 is attached to the case 20 by display. More specifically, the identifier 70 is printed directly on the case 20. The identifier 70 is also located on the side 22 of the case 20. In this embodiment, the identifier 70 is a matrix-type two-dimensional code.

(2.2) Manufacturing method Next, the manufacturing method (production method) of the capacitor 1 will be described with reference to FIGS. 6 to 9.

Capacitor 1 is manufactured by capacitor manufacturing system 100 shown in FIG. The capacitor manufacturing system 100 sequentially manufactures a plurality of capacitors 1 in an assembly line manner. The manufacturing speed of the capacitor 1 by the capacitor manufacturing system 100 is, for example, about 180 pieces/minute.

The method for manufacturing the capacitor 1 includes a plurality of steps, and the capacitor 1 is manufactured by performing the plurality of steps in a predetermined order. Capacitor manufacturing system 100 includes multiple devices to perform multiple steps. The plurality of devices include, for example, a winding machine for performing the lead connection step S11 and the winding step S12, a chemical conversion tank used in the cross-sectional chemical formation step S16, an inkjet printer for printing the display section 60, etc. Contains.

Capacitor manufacturing system 100 is communicably connected to management system 200. The management system 200 includes, for example, a microcomputer having a processor and a memory. Various functions of the management system 200 are realized by the processor of the microcomputer executing programs recorded in the memory. The program executed by the processor of the management system 200 may be recorded in advance in the memory of the microcomputer, may be provided recorded on a recording medium such as a memory card, or may be provided through a telecommunications line. Good too.

The management system 200 includes a database 210 that records management information. The database 210 may be the same as the memory described above, or may be another electrically rewritable recording medium.

Further, the capacitor manufacturing system 100 is communicably connected to a measurement system 300 that measures the state of devices in the capacitor manufacturing system 100. The measurement system 300 acquires information on the state of the capacitor manufacturing system 100 (for example, drive speed of the device, temperature, etc.) and information on the environment (for example, temperature, humidity, etc.) by measurement. Specifically, the measurement system 300 measures, for example, the winding speed of the capacitor element 10 by the winding machine, the temperature of the chemical conversion tank/voltage applied to the chemical conversion tank, the temperature of the environment, and the humidity. The information acquired by the measurement system 300 is stored in the database 210 of the management system 200 in chronological order along with the time at which it was acquired.

Further, the capacitor manufacturing system 100 is communicably connected to the inspection system 400. The inspection system 400 inspects the capacitor 1 manufactured by the capacitor manufacturing system 100 (including intermediate products in the middle of manufacturing).

As shown in FIG. 6, the test system 400 includes a withstand voltage test system 410 for testing the withstand voltage of the capacitor element 10. The inspection system 400 also inspects, for example, whether the dimensions of the anode lead terminal 14 and the cathode lead terminal 15 are within a desired range. For example, the inspection system 400 inspects whether the height of the sealing member 30 is within a desired range. For example, the inspection system 400 inspects whether the convergence current value is within a desired range in chemical conversion treatment. For example, the inspection system 400 inspects whether the aperture shape of the case 20 has a desired shape. For example, the inspection system 400 inspects whether the display section 60 of a desired shape is attached to the top surface 21 of the case 20. The inspection system 400 inspects, for example, whether the capacitance value, inductive tangent (tan δ), equivalent series resistance (ESR), leakage current (LC), etc. are within desired ranges. Element members whose test results by the test system 400 do not show desired performance are removed from the manufacturing process as appropriate. Information on test results obtained by the test system 400 is stored in the database 210 of the management system 200 in chronological order along with the time when the test was performed.

FIG. 7 is a flowchart showing a method for manufacturing capacitor 1. As shown in FIG. 7, the manufacturing method of the capacitor 1 includes a lead connection step S11, a winding step S12, a pressure test step S13, a rubber assembly step S14, a holding step S15, a cross section forming step S16, and a polymer It includes a process S17, a removal process S18, an assembly process S19, a drawing process S20, an identifier provision process S21, an aging process S22, a printing process S23, and a processing process S24.

First, before the lead connection step S11, the anode foil 11 is prepared by subjecting a metal foil (aluminum foil) of a predetermined size to etching treatment and chemical conversion treatment, and cutting it into a desired size. Further, the cathode foil 12 is prepared by cutting a metal foil (aluminum foil) of a predetermined size into a desired size.

In the lead connection step S11, the lead tab 141 of the anode lead terminal 14 is connected to the anode foil 11 by, for example, caulking or ultrasonic welding. Further, the lead tab 151 of the cathode lead terminal 15 is connected to the cathode foil 12 by, for example, caulking or ultrasonic welding.

In the winding step S12, the anode foil 11, one of the pair of separators 13, the cathode foil 12, and the other of the pair of separators 13 are arranged in an overlapping manner. Then, the anode foil 11, the cathode foil 12, and the pair of separators 13 are wound up into a roll to produce a capacitor element (rolled element) 10.

In the withstand voltage test step S13, the withstand voltage between the pair of electrodes 101 and 102 of the capacitor element 10 is tested. The withstand voltage test step S13 will be explained in the column "(2.3) Withstand voltage test step".

In this way, the capacitor element 10 is manufactured through the lead connection step S11 to the withstand voltage test step S13.

In the rubber assembly step S14, the sealing member 30 is attached to the capacitor element 10. The sealing member 30 is attached to the capacitor element 10 by inserting the anode lead terminal 14 and the cathode lead terminal 15 of the capacitor element 10 into the two through holes of the sealing member 30, respectively.

In the holding step S15, the capacitor elements 10 to which the sealing members 30 are attached are sequentially held by a band-shaped holder. The holder is, for example, a metal carrier bar. The anode lead terminals 14 of the capacitor elements 10 are held (for example, welded) to the holder so that the height directions of the capacitor elements 10 are aligned with each other. A plurality of capacitor elements 10 held by one holder constitute one production lot. One production lot includes, for example, about 10,000 to 50,000 capacitor elements 10.

In the cross-sectional chemical formation step S16, the anode foil 11 of the capacitor element 10 is subjected to a chemical conversion treatment. In the cross-sectional chemical formation step S16, for example, a plurality of capacitor elements 10 held by a holder (carrier bar) are immersed in a chemical liquid in a chemical conversion tank, and a voltage is applied between the holder and the chemical liquid. Perform chemical conversion treatment. In the cross-sectional chemical formation step S16, the dielectric film 16 is formed on the cut surface of the anode foil 11 formed by cutting, and cracks in the dielectric film 16 that may occur in the winding step S12 and the like are repaired. In the cross-sectional chemical conversion step S16, after the chemical conversion treatment, the capacitor element 10 may be cleaned and dried as necessary.

In the polymer step S17, a conductive polymer is attached to at least a portion of at least one of the surface of the anode foil 11 (dielectric film 16), the surface of the cathode foil 12, and the surface of the separator 13. In the polymer step S17, for example, the capacitor element 10 held by the holder is immersed in a dispersion liquid in which a conductive polymer is dispersed in a solvent, and the dispersion liquid is permeated into the entire interior of the capacitor element 10, thereby forming the capacitor element. 10 is taken out from the dispersion. The capacitor element 10 impregnated with the dispersion liquid is then subjected to heat treatment to volatilize at least a portion of the solvent and aggregate the conductive polymer.

In the removal step S18, the capacitor element 10 is removed from the holder. In the removal step S18, the anode lead terminal 14 held by the holder is removed from the holder (if the anode lead terminal 14 is welded to the holder, for example, the anode lead terminal 14 is removed at a portion of an appropriate length). It is done by cutting).

In the assembly process S19, the case 20 is individually attached to the capacitor element 10 that has been removed from the holder. The capacitor element 10 removed from the holder is individually inserted into a case (exterior) 20 filled with an electrolytic solution (electrolyte 40).

In the drawing step S20, the case 20 is sealed by the sealing member 30 by performing a drawing process to squeeze a portion of the side wall of the case 20 that corresponds to the sealing member 30. As a result, an assembly in which the case 20 is attached to the capacitor element 10 is manufactured.

In the identifier attaching step S21, identifiers 70 are sequentially attached to the case 20 of the assembly. In the identifier adding step S21, the identifier 70 is printed on the side surface 22 of the case 20 of the assembly using, for example, an inkjet printer. The assembly to which the identifier 70 has been assigned is stored in a storage box (first storage box).

In the aging step S22, an arbitrary assembly is taken out from the first storage box, and the identifier 70 of the taken out assembly is read. Then, in the order in which the identifiers 70 are read, a voltage is applied between the anode lead terminal 14 and the cathode lead terminal 15 of the assembly, thereby performing reconversion treatment on the dielectric film 16. In the aging step S22, the assembly is appropriately heated as necessary. The assembly that has undergone the reconstitution treatment is stored in a storage box (second storage box).

In the printing step S23, an arbitrary assembly is taken out from the second storage box, and the identifier 70 of the taken out assembly is read. Then, in the order in which the identifiers 70 are read, the display portions 60 are printed on the top surface 21 of the case 20 of the assembly by an inkjet printer. The assembly on which the display section 60 is printed is stored in a storage box (third storage box).

In the processing step S24, an arbitrary assembly is taken out from the third storage box, and the identifier 70 of the taken out assembly is read. The seat plates 50 are then attached to the assembly in the order in which the identifiers 70 are read. In the processing step S24, the anode lead terminal 14 and cathode lead terminal 15 of the assembly are inserted into the two through holes of the seat plate 50, thereby attaching the seat plate 50 to the assembly. Further, after the seat plate 50 is attached, the anode lead terminal 14 and the cathode lead terminal 15 are bent outward, so that the bent portions of each lead terminal are inserted into the two housing recesses of the seat plate 50. 152, respectively.

Capacitor 1 is manufactured by the procedure described above.

Here, in the manufacturing method of the capacitor 1 of this embodiment, the order of the plurality of assemblies (capacitor elements 10) to be processed does not change in the steps up to the identifier assignment step S21. In each step (S11 to S21), the time required for processing is known, and these steps are performed continuously. Therefore, if it is known when (date and time) the identifier 70 was added in the identifier adding step S21, it is possible to know which process was performed on the assembly to which the identifier 70 was added at what point. In other words, knowing the time when identifier 70 was applied to an assembly, it is possible to determine the time when any device in capacitor manufacturing system 100 was processing this assembly.

Furthermore, in the manufacturing method of this embodiment, the identifier 70 assigned to each assembly in the identifier assignment step S21 is stored in the database 210 of the management system 200 in chronological order along with the time at which the identifier 70 was assigned. Therefore, after the capacitor 1 is completed, it is possible to know when each process (S11 to S21) was performed on the capacitor 1 by simply reading the identifier 70 of the capacitor 1.

In addition, in the manufacturing method of this embodiment, in each step after the aging step S22, the identifier 70 of the assembly is first read, and the read identifier 70 is stored in the database 210 of the management system 200 along with the time when the identifier 70 was read. are stored in chronological order. Therefore, after the capacitor 1 is completed, by simply reading the identifier 70 of the capacitor 1, it is possible to know when each process (S22 to S24) was performed on the capacitor 1.

Furthermore, as described above, information on measurement results by the measurement system 300 is stored in the database 210 of the management system 200 in chronological order. Therefore, by simply reading the identifier 70 of the capacitor 1 after the capacitor 1 is completed, the state of the equipment when the capacitor 1 was being manufactured (the state of the capacitor manufacturing system 100 at the time of manufacturing the capacitor 1) can be obtained from the database 210. It becomes possible to read the data.

Furthermore, the database 210 of the management system 200 stores information on measurement results by the inspection system 400 in chronological order, as described above. Therefore, after the capacitor 1 is completed, by simply reading the identifier 70 of the capacitor 1, it is possible to read the information on the test results of the capacitor 1 by the test system 400 from the database 210.

(2.3) Withstand voltage test step The withstand voltage test step S13 in the manufacturing method of the capacitor 1 will be described in more detail below.

In the withstand voltage test step S13, the withstand voltage (withstand voltage) between the pair of electrodes 101 and 102 of the capacitor element 10 is tested. The withstand voltage of the capacitor element 10 indicates the upper limit of the voltage that can be applied between the pair of electrodes 101 and 102 of the capacitor 1.

The withstand voltage testing step S13 of the present embodiment is a method for testing the capacitor element 10, and as shown in FIG. 1, includes a voltage application step ST1 and a measuring step ST2. The voltage application step ST1 includes applying an applied voltage V0 that increases with time between the pair of electrodes 101 and 102 of the capacitor element 10 until discharge occurs between the pair of electrodes 101 and 102. . The measurement step ST2 includes measuring the applied voltage V0 when a discharge occurs between the pair of electrodes 101 and 102 in the voltage application step ST1 as the discharge voltage Vsp.

The voltage resistance test step S13 of this embodiment further includes a recording step ST3. The recording step ST3 includes recording the discharge voltage Vsp measured in the measuring step ST2 on a recording medium.

The withstand voltage test step S13 of this embodiment further includes a withstand voltage determination step ST4. The breakdown voltage determination step ST4 includes, after the measurement step ST2, applying a voltage equal to or lower than a predetermined determination voltage V _judge between the pair of electrodes 101 and 102 to determine the breakdown voltage of the capacitor element 10.

(2.3.1) Matters to be considered The inventors of the present application conducted various studies when implementing the voltage resistance test step S13. First, the contents of the considerations made by the inventors of the present application will be explained.

(2.3.1.1) Distance between electrodes As described above, the withstand voltage of the capacitor 1 is determined depending on the distance (shortest distance) between the anode 101 and the cathode 102. However, the capacitor element 10 is formed by stacking an anode foil 11, a cathode foil 12, and a separator 13 and winding them together. Therefore, it is difficult to actually measure the distance (shortest distance) between the anode 101 and the cathode 102. Furthermore, if there is a burr 91 or the like on the anode foil 11 or the cathode foil 12, or if a foreign object 92 exists between the anode foil 11 and the cathode foil 12, the substantial distance between the anode 101 and the cathode 102 may be reduced. It can change.

Therefore, the inventors of the present invention first investigated how to indirectly determine the distance between the electrodes 101 and 102 of the capacitor element 10.

In conducting the study, the inventors of the present invention created a model device 110 as shown in FIG. As shown in FIG. 8, the model device 110 includes a needle-like electrode 111 and a plate-like electrode 112 that are arranged to face each other, and the distance D1 between the needle-like electrode 111 and the plate-like electrode 112 is It is configured to be changeable using a micrometer.

In addition, the inventors of the present invention manufactured a voltage application device 450 as shown in FIG. The voltage application device 450 is a device for applying a voltage that increases over time to the model device 110. As shown in FIG. 9, the voltage application device 450 includes a constant current source CI11, a first switch SW11 and a second switch SW12, a capacitive element (capacitor) C11, a voltage measuring device VM11, a detector DT11, It includes a pair of output terminals T11, T11 and a control section 451.

A series circuit including a first switch SW11 and a second switch SW12 is connected between both ends of the constant current source CI11. Specifically, the high potential side terminal of the constant current source CI11 is connected to the first switch SW11, and the low potential side terminal of the constant current source CI11 is connected to the second switch SW12. Each of the first switch SW11 and the second switch SW12 is a semiconductor switch, and is, for example, an FET (Field Effect Transistor). The capacitive element C11 is connected between both ends of the second switch SW12. Further, a pair of output terminals T11, T11 are connected to both ends of the capacitive element C11, respectively. Further, a voltage measuring device VM11 is used to measure the voltage between both ends of the capacitive element C11. Voltage measuring device VM11 measures the voltage between a pair of output terminals T11, T11. The voltage measuring device VM11 measures the voltage between the pair of output terminals T11 and T11 in real time, and transmits the measured voltage value to the control unit 451. Furthermore, a detector DT11 is connected to one of the pair of output terminals T11, T11. Detector DT11 detects the occurrence of discharge between the pair of output terminals T11, T11. The detector DT11 is, for example, a current sensor such as a CT. The control unit 451 controls on/off of the first switch SW11 and the second switch SW12. Furthermore, the control unit 451 receives the measurement results of the voltage measuring device VM11 and the detection results of the detector DT11.

The operation of voltage application device 450 will be explained with reference to FIG. 10. FIG. 10 is an explanatory diagram showing temporal changes in the voltage (output voltage V10) between the pair of output terminals T11, T11.

In the initial state, the first switch SW11 is turned off and the second switch SW12 is turned on by the control unit 451 (time t10). As a result, the charge accumulated in the capacitive element C11 is discharged through the electric circuit connected between the pair of output terminals T11, and the output voltage V10 becomes 0V.

The control unit 451 first turns on the first switch SW11 and turns off the second switch SW12 (time t11). As a result, charge is supplied to the capacitive element C11 from the constant current source CI11, and the voltage across the capacitive element C11 increases as time passes. Therefore, the output voltage V10 also increases over time. Note that the rate of increase in the output voltage V10 can be adjusted by controlling the switching of the first switch SW1 and adjusting its duty ratio. That is, in the voltage application step (ST1), the current from the constant current source CI11 can be passed through the capacitor via the first switching SW11, so the rate of increase in the output voltage V10 can be controlled.

When the output voltage V10 increases until it reaches the breakdown voltage of the electric circuit connected between the pair of output terminals T11, T11, a discharge occurs in the electric circuit (time t12). When discharge occurs, the pair of output terminals T11 and T11 are short-circuited, and the charge accumulated in the capacitive element C11 flows through the short-circuited electric circuit. Therefore, a large current flows through the detector DT11. The detector DT11 detects the occurrence of discharge in the electric circuit by detecting the occurrence of this large current. When detecting the occurrence of discharge, the detector DT11 transmits a discharge detection signal indicating the detection of the occurrence of discharge to the control unit 451.

Upon receiving the discharge detection signal, the control unit 451 acquires the value of the voltage (output voltage V10) measured by the voltage measuring device VM11 when the discharge occurs as the discharge voltage Vsp. The discharge voltage Vsp is ideally the value of the output voltage V10 immediately before discharge occurs. Here, the discharge voltage Vsp is obtained, for example, as the maximum value of the measured output voltage V10 in a specified period. The prescribed period is, for example, a predetermined period (for example, several milliseconds) that includes and precedes the time when the control unit 451 receives the discharge detection signal.

Further, upon receiving the discharge detection signal, the control unit 451 turns off the first switch SW1 and turns on the second switch SW2 (time t13). As a result, the pair of output terminals T11, T11 are electrically disconnected from the capacitive element C11, so that the application of voltage between the pair of output terminals T11, T11 is stopped. Further, capacitive element C11 is disconnected from constant current source CI11.

The inventors connected the model device 110 between the pair of output terminals T11, T11 of the voltage application device 450, and measured the discharge voltage Vsp while variously changing the distance D1 between the electrodes. The results are shown in FIG. In this study, the rate of increase of the output voltage V10 was fixed at 4.0 V/ms, and the discharge voltage Vsp was measured 10 times for each case where the distance D1 between the electrodes was 5 μm, 10 μm, 15 μm, and 20 μm.

In FIG. 11, the horizontal axis shows the distance D1 [μm] between the electrodes, and the vertical axis shows the discharge voltage Vsp [V]. Furthermore, in FIG. 11, the black circles indicate the average value of the 10 measured values at each distance D1, and the bars above and below the black circles indicate the maximum and minimum values.

As can be seen from FIG. 11, a substantially linear relationship is established between the distance D1 between the electrodes and the discharge voltage Vsp. Therefore, once the discharge voltage Vsp is determined, the distance D1 between the electrodes can be determined indirectly. That is, by determining the discharge voltage Vsp of the capacitor element 10, the distance between the pair of electrodes 101 and 102 (for example, if one electrode has a burr 91, the distance between the tip of the burr 91 and the other electrode) can be determined. , it has been found that it can be determined indirectly. Further, by determining the dispersion (distribution) of the discharge voltage Vsp of the plurality of capacitor elements 10, it is possible to determine the dispersion of the distance between the electrodes 101 and 102, and furthermore, the presence or absence of the burr 91 or foreign object 92 and the dispersion of its size. can.

(2.3.1.2) Rate of Increase in Voltage Next, the inventors of the present application investigated the rate of increase v _in of the voltage applied between the electrodes.

In conducting the study, the present inventors measured the discharge voltage Vsp using the voltage application device 450 and the model device 110 while variously changing the rate of increase v _in of the output voltage V10. The results are shown in FIG. In this study, the distance D1 between the electrodes was fixed at 10 μm, and the increase rate v _in of the output voltage V10 was 3.0 V/ms, 5.0 V/ms, and 10.0 V/ms, 10 times each. The discharge voltage Vsp was measured.

Here, in order to achieve a severe (high-speed) voltage increase speed of 3.0 V/ms to 10.0 V/ms, the inventors of the present application have developed a capacitor C11, a constant current source CI11, a switching element (the first switch ) A newly developed voltage application device (boosting device) using SW11. In other words, it is not possible to achieve such a severe voltage increase speed with voltage control of a general power supply, and in a CR circuit with a resistor, the waveform becomes dull as the capacitor voltage increases, so the discharge time becomes longer. In contrast, in this voltage application device, by controlling the switching element (first switch) SW11 by the control unit 451, it is possible to severely control the voltage increase rate.

In FIG. 12, the horizontal axis shows the rate of increase in voltage v _in [V/ms], and the vertical axis shows the discharge voltage Vsp [V]. Moreover, in FIG. 12, the diamond indicates the average value of 10 measured values at each increasing speed v _in , and the bars above and below the diamond indicate the maximum and minimum values.

As can be seen from FIG. 12, the variation from the average value is greater when the increasing rate v _in is 5.0 V/ms or 10.0 V/ms than when the increasing rate v _in is 3.0 V/ms. was big. Moreover, the variation was about the same when the increasing speed v _in was 5.0 V/ms and when it was 10.0 V/ms. From this result, it was found that when the voltage increase rate v _in was greater than 5.0 V/ms, the dispersion of the discharge voltage Vsp became large.

The reason why the dispersion in the discharge voltage Vsp increases as the increase rate v _in increases is because the time from when the output voltage V10 reaches the discharge voltage Vsp until the actual discharge occurs (the ionization of electrons required for the discharge to occur) This is presumed to be because the voltage may increase faster than the time (time required for electrons to move through the circuit and time for electrons to move through the circuit).

(2.3.1.3) Effect of inter-electrode discharge The inventors of the present invention also investigated the effect on the withstand voltage of the capacitor element 10 when a discharge occurs between the electrodes 101 and 102 of the capacitor element 10. Study was carried out.

In the study, the inventors extracted 20 capacitor elements 10 (rated withstand voltage 50V) manufactured by the capacitor manufacturing system 100, and applied the discharge voltage Vsp1 to each capacitor element 10 using the voltage application device 450 described above. It was measured. Furthermore, after the discharge of each capacitor element 10, the output voltage V10, which increases over time, was applied again, and the discharge voltage Vsp2 was measured. The results are shown in FIGS. 13A and 13B. In this study, the rate of increase in the output voltage V10 was fixed at 4.0 V/ms, and the discharge voltages Vsp1 and Vsp2 were measured.

13A shows the distribution of the first discharge voltage Vsp1 for the 20 capacitor elements 10, and FIG. 13B shows the distribution of the second discharge voltage Vsp2 for the 20 capacitor elements 10.

As can be seen from FIGS. 13A and 13B, the average value of the discharge voltage was larger in the distribution of the second discharge voltage Vsp2 than in the distribution of the first discharge voltage Vsp1. That is, it has been found that by generating a discharge between the pair of electrodes 101 and 102, the distance between the electrodes 101 and 102 increases, that is, the withstand voltage increases.

Furthermore, as can be seen from FIGS. 13A and 13B, the distribution of the second discharge voltage Vsp2 had smaller variations in discharge voltage than the distribution of the first discharge voltage Vsp1. That is, the difference between the maximum value and the minimum value of the second discharge voltage Vsp2 was smaller than the difference between the maximum value and the minimum value of the first discharge voltage Vsp1. Furthermore, the dispersion of the second discharge voltage Vsp1 was smaller than the dispersion of the first discharge voltage Vsp1. That is, it has been found that by generating a discharge between the pair of electrodes 101 and 102, variations in the distance between the electrodes 101 and 102 are reduced, that is, variations in breakdown voltage are reduced.

The distance between the electrodes 101 and 102 (the shortest distance ) has become substantially larger, and the variation in distance has become smaller.

(2.3.2) Inspection System Next, the figure shows a pressure-resistant inspection system 410 (hereinafter also simply referred to as "inspection system 410") for carrying out the pressure-resistant inspection process S13, which was invented based on the above considerations. This will be explained with reference to 14. Inspection system 410 is a system for inspecting capacitor element 10 used in capacitor 1.

As shown in FIG. 14, the inspection system 410 includes a constant current source CI1, a constant voltage source CV1, a first switch SW1 to a fourth switch SW4, a capacitive element (capacitor) C1, a voltage measuring device VM1, It includes a detector DT1, a pair of output terminals T1, T1, and a control section 411. Each of the first switch SW1 to the fourth switch SW4 is a semiconductor switch, for example, a FET (Field Effect Transistor).

The low potential side terminal of the constant current source CI1 is connected to the low potential side terminal of the constant voltage source CV1. The high potential side terminal of the constant current source CI1 is connected to the high potential side terminal of the constant voltage source CV1 via a series circuit of the first switch SW1 and the fourth switch SW4. Note that the first switch SW1 is connected to the constant current source CI1, and the fourth switch SW4 is connected to the constant voltage source CV1.

The capacitive element C1 is connected between both ends of a series circuit of the constant voltage source CV1 and the fourth switch SW4. The constant voltage source CV1 outputs a constant voltage having a voltage value Vi. Further, a series circuit including a second switch SW2 and a third switch SW3 is connected between both ends of the capacitive element C1. Note that the second switch SW2 is connected to the low potential side terminal of the capacitive element C1, and the third switch SW3 is connected to the high potential side terminal of the capacitive element C1.

A pair of output terminals T1, T1 are connected to both ends of the second switch SW2. A pair of electrodes 101 and 102 of the capacitor element 10 to be inspected are connected to the pair of output terminals T1 and T1, respectively.

Further, a voltage measuring device VM1 is used to measure the voltage between both ends of the second switch SW2. Voltage measuring device VM1 measures the voltage between a pair of output terminals T1, T1. The voltage measuring device VM1 measures the voltage between the pair of output terminals T1, T1 in real time, and transmits the measured voltage value to the control unit 411.

A detector DT1 is connected to one of the pair of output terminals T1, T1. Detector DT1 detects the occurrence of discharge between the pair of output terminals T1, T1. The detector DT1 is, for example, a current sensor such as a CT. When detecting the occurrence of discharge, the detector DT1 transmits a discharge occurrence signal to the control unit 411.

The control unit 411 controls on/off of the first switch SW1 to the fourth switch SW4. Further, the control unit 411 receives the measurement results of the voltage measuring device VM1 and the detection results of the detector DT1. The control unit 411 includes, for example, a computer system. A computer system mainly consists of a processor and a memory as hardware. The function of the control unit 411 is realized by the processor executing a program recorded in the memory of the computer system. The program may be pre-recorded in the memory of the computer system, provided through a telecommunications line, or recorded on a non-transitory storage medium readable by the computer system, such as a memory card, optical disc, or hard disk drive. may be provided. The control unit 411 may be realized by, for example, a PLC (Programmable Logic Controller).

In short, the inspection system 410 includes a voltage application section 412 and a measurement section 413, as shown in FIG. The voltage application unit 412 applies an applied voltage V0 that increases over time between the pair of electrodes 101 and 102 of the capacitor element 10 until discharge occurs between the pair of electrodes 101 and 102. The measurement unit 413 measures the applied voltage V0 when discharge occurs between the pair of electrodes 101 and 102 as the discharge voltage Vsp. Here, the voltage application section 412 includes a pair of output terminals T1, T1, a capacitive element C1, a third switch SW3, a detector DT1, and a control section 411. Furthermore, the measurement unit 413 includes a voltage measuring device VM1 and a control unit 411.

(2.3.3) Withstand voltage test Next, a method of testing the withstand voltage between the pair of electrodes 101 and 102 of the capacitor element 10 using the test system 410 will be described with reference to FIG. FIG. 16 is an explanatory diagram showing a temporal change in the voltage between the pair of output terminals T1, T1 (the applied voltage V0 applied to the capacitor element 10).

In the initial state, the control unit 411 turns off the first switch SW1 and the third switch SW3, and turns on the second switch SW2 and the fourth switch (time t0). Further, a capacitor element 10 is connected between the pair of output terminals T1, T1. By turning off the first switch SW1 and turning on the fourth switch SW4, the constant voltage source CV1 is connected between both ends of the capacitive element C1. Therefore, charge is supplied to the capacitive element C1 from the constant voltage source CV1, and the voltage across the capacitive element C1 rises to the voltage value Vi of the voltage of the constant voltage source CV1. On the other hand, when the third switch SW3 is turned off, the pair of output terminals T1 and T1 are separated from the capacitive element C1, and when the second switch SW2 is turned on, the accumulation inside the capacitor element 10 is Charge is discharged. Therefore, the voltage between the pair of output terminals T1, T1 (applied voltage V0) becomes 0V.

The control unit 411 first turns on the first switch SW1 and the third switch SW3, and turns off the second switch SW2 and the fourth switch SW4 (time t1). As a result, an applied voltage V0 corresponding to the voltage across the capacitive element C1 (here, voltage value Vi>0) is applied between the pair of electrodes 101 and 102 of the capacitor element 10. That is, the initial voltage is greater than 0V.

Furthermore, since charge is supplied to the capacitive element C1 from the constant current source CI1, the voltage across the capacitive element C1 increases over time. Therefore, the applied voltage V0 applied between the pair of electrodes 101 and 102 increases over time. Note that the rate of increase in the applied voltage V0 can be adjusted by controlling the switching of the first switch SW1 and adjusting its duty ratio. Based on the considerations in the column “(2.3.1.2) Voltage increase rate”, the increase rate of the applied voltage V0 is set, for example, in the range of 0.2V/ms to 4.0V/ms. , here set to 4.0V/ms.

Also, in this inspection, as discussed in the section "(2.3.1.2) Voltage increase rate", the capacitor C1, constant current source CI1, and switching element (first switch SW1) are used to control the By controlling the switching of the switching element in the section 411, it is possible to severely control the voltage increase speed. That is, in the voltage application step ST1, the rate of increase v in of the applied voltage V0 is increased by flowing current from the constant current source CI1 to the pair of electrodes 101 and 102 via a switching element (first switch SW1) whose switching is _controlled . Including controlling.

When the applied voltage V0 increases until it reaches the breakdown voltage of the capacitor element 10, a discharge occurs between the pair of electrodes 101 and 102 (time t2). When discharge occurs, the pair of electrodes 101 and 102 of the capacitor element 10 are short-circuited, and the charge stored in the capacitive element C1 flows through the capacitor element 10. Therefore, a large current flows through the detector DT1. The detector DT1 detects the occurrence of discharge in the capacitor element 10 by detecting the occurrence of this large current. When detecting the occurrence of discharge, the detector DT1 transmits a discharge detection signal indicating the detection of the occurrence of discharge to the control unit 411.

Upon receiving the discharge detection signal, the control unit 411 acquires the value of the applied voltage V0 that was measured by the voltage measuring device VM11 when the discharge occurred as the discharge voltage Vsp. The discharge voltage Vsp is ideally the value of the applied voltage V0 immediately before discharge occurs. Here, the discharge voltage Vsp is obtained, for example, as the maximum value of the measured applied voltage V0 in a specified period. The prescribed period is, for example, a predetermined period (for example, several milliseconds) that includes and precedes the time when the control unit 411 receives the discharge detection signal.

The control unit 411 records the obtained discharge voltage Vsp on a recording medium. The recording medium may be, for example, a memory included in a computer system that constitutes the control unit 411, or may be a recording device separate from the control unit 411. Further, the control unit 411 causes the database 210 of the management system 200 to store the acquired discharge voltage Vsp in chronological order along with the acquired time.

Further, upon receiving the discharge detection signal, the control unit 411 turns off the first switch SW1 and the third switch SW3, and turns on the second switch SW2 and the fourth switch SW4 (time t3). As a result, the capacitor element 10 is electrically disconnected from the capacitive element C1, so that the application of voltage to the capacitor element 10 is stopped. Furthermore, since the constant voltage source CV1 is connected across the capacitive element C1, charge is supplied to the capacitive element C1 from the constant voltage source CV1, and the voltage across the capacitive element C1 is the constant voltage source CV1. The voltage increases to a voltage value Vi.

Next, the control unit 411 turns on the first switch SW1 and the third switch SW3, and turns off the second switch SW2 and the fourth switch SW4 (time t4). As a result, an applied voltage V0 corresponding to the voltage across the capacitive element C1 (voltage value Vi here) is applied between the pair of electrodes 101 and 102 of the capacitor element 10. Further, charge is supplied to the capacitive element C1 from the constant current source CI1, and the voltage across the capacitive element C1 increases as time passes. Therefore, the applied voltage V0 applied between the pair of electrodes 101 and 102 increases over time.

Thereafter, the control unit 411 keeps the first switch SW1 to the fourth switch SW4 in the on/off state until the applied voltage V0 reaches the determination voltage V _judge (time t5) or until discharge occurs between the pair of electrodes 101 and 102. maintain. When the applied voltage V0 reaches _the judgment voltage Vjudge, the control unit 411 determines that the withstand voltage of the capacitor element 10 is equal to or higher than the judgment voltage _Vjudge , there is no problem with the withstand voltage, and the capacitor element 10 is a good product. . On the other hand, if discharge occurs between the pair of electrodes 101 and 102 before the applied voltage V0 reaches the determination voltage _Vjudge , the control unit 411 determines that the capacitor element 10 is a defective product.

The control unit 411 turns off the first switch SW1 and the third switch SW3, turns on the second switch SW2 and the fourth switch SW4, and ends the inspection.

(2.3.4) Advantages As described above, according to the withstand voltage test step S13 of this embodiment, a discharge is generated between the pair of electrodes 101 and 102, and the discharge voltage Vsp is measured. Therefore, it is possible to grasp the state of the capacitor element 10 before applying the voltage.

Further, according to the withstand voltage test step S13, the determination voltage V _judge is applied between the pair of electrodes 101 and 102 after the discharge is generated. Therefore, it is possible to eliminate capacitor elements 10 that are defective due to discharge, and it is possible to improve the quality of the capacitor elements 10.

Further, according to the withstand voltage test step S13, the applied voltage V0 is increased over time from an initial voltage greater than 0V. Therefore, it is possible to shorten the inspection time. For example, although there are variations in the discharge voltage Vsp of the capacitor element 10 (see FIG. 13A), there is a certain lower limit value. Therefore, by using this lower limit value as the initial voltage, the inspection time can be shortened.

Further, in the case of the capacitor element 10 of the present disclosure, the discharge voltage Vsp is about 400V, and the rate of increase v _in of the applied voltage V0 by the inspection system 410 is preferably 0.2V/ms to 4.0V/ms. Therefore, the time required to test one capacitor element 10 is about 100 ms to 2 seconds. Therefore, in the case of a capacitor manufacturing system 100 that produces approximately tens of thousands of capacitors per day, it is possible to inspect all capacitors 1 manufactured (total inspection). Note that the pressure resistance test step may be performed multiple times.

(2.4) Management Method Next, a method of managing the capacitor 1 using the above inspection method will be described.

The management method of this embodiment is a management method for the capacitor 1 manufactured by the capacitor manufacturing system 100. The management method is executed by the management system 200, for example. The management method includes performing the testing method described in the section "(2.3) Withstand voltage testing process" on a plurality of capacitor elements 10. In particular, the plurality of capacitor elements 10 on which the testing method is performed include the capacitor elements 10 of all capacitors 1 manufactured by the capacitor manufacturing system 100.

As described above, the database 210 of the management system 200 stores the discharge voltage Vsp of the capacitor element 10 of each capacitor 1 measured by the withstand voltage test system 410 together with the measured time.

Further, the database 210 of the management system 200 stores the identifier 70 of each capacitor 1 over time. Then, the management system 200 classifies the plurality of capacitors 1 based on the identifier 70, for example, the plurality of capacitors 1 are classified so that the plurality of capacitors 1 included in one production lot constitute one capacitor group. Classify. Furthermore, the management system 200 determines the distribution of the discharge voltage Vsp for each capacitor group.

This makes it possible for the management system 200 (or its user) to grasp changes in the manufacturing conditions of the capacitor element 10 by looking at temporal changes in the dispersion of the discharge voltage Vsp of the capacitor group.

For example, variations (for example, dispersion) in the discharge voltage Vsp of a capacitor element group constituted by a plurality of capacitor elements 10 each having an anode foil 11 or a cathode foil 12 cut from the same metal foil are different from those of other capacitor element groups. Suppose that it is larger than the dispersion of . In this case, the management system 200 may determine that the cause of the variation in the discharge voltage Vsp is, for example, the metal foil that is the material of the anode foil 11 or the cathode foil 12 (for example, the foil is highly sticky). It is possible. The management system 200 can also determine, for example, that there is a possibility that the dispersion in the discharge voltage Vsp may be large even for a group of capacitor elements manufactured using metal foils having similar characteristics. .

Further, for example, suppose that the dispersion in the discharge voltage Vsp of the capacitor element group is increasing day by day. In this case, the management system 200 can determine that the cause of the variation in the discharge voltage Vsp is, for example, aging deterioration of the capacitor manufacturing system 100.

In short, the management method of this embodiment further includes a management step. The management step includes managing the states of the plurality of capacitor elements 10 based on the measured discharge voltages Vsp of the plurality of capacitor elements 10.

Further, the management process includes a classification process and a variation management process. The classification step includes classifying the plurality of capacitor elements 10 into a plurality of capacitor element groups each including two or more capacitor elements, based on the manufacturing conditions at the time of manufacturing the plurality of capacitor elements 10 by the capacitor manufacturing system 100. . The variation management step includes determining, for at least one of the plurality of capacitor element groups, the distribution of the discharge voltage Vsp of two or more capacitor elements 10 included in the capacitor element group.

According to the management method of this embodiment, there is an advantage that the state of the capacitor manufacturing system 100 can be easily managed.

(3) Modifications The above embodiment is just one of various embodiments of the present disclosure. The embodiments described above can be modified in various ways depending on the design, etc., as long as the objective of the present disclosure can be achieved. Furthermore, the same functions as the control unit 411 or the management system 200 according to the embodiments described above may be realized by a computer program, a non-temporary recording medium on which a computer program is recorded, or the like.

Modifications of the above embodiment will be listed below. The modified examples described below can be applied in combination as appropriate.

The control unit 411 of the inspection system 410 in the capacitor manufacturing system 100 according to the present disclosure includes a computer system. A computer system mainly consists of a processor and a memory as hardware. The function of the control unit 411 in the present disclosure is realized by the processor executing a program recorded in the memory of the computer system. The program may be pre-recorded in the memory of the computer system, may be provided through a telecommunications line, or may be recorded on a non-transitory storage medium readable by the computer system, such as a memory card, optical disc, hard disk drive, etc. may be provided. A processor in a computer system is comprised of one or more electronic circuits including semiconductor integrated circuits (ICs) or large scale integrated circuits (LSIs). The integrated circuits such as IC or LSI referred to herein have different names depending on the degree of integration, and include integrated circuits called system LSI, VLSI (Very Large Scale Integration), or ULSI (Ultra Large Scale Integration). Furthermore, an FPGA (Field-Programmable Gate Array), which is programmed after the LSI is manufactured, or a logic device that can reconfigure the connections inside the LSI or reconfigure the circuit sections inside the LSI, may also be used as a processor. Can be done. The plurality of electronic circuits may be integrated into one chip, or may be provided in a distributed manner over a plurality of chips. A plurality of chips may be integrated into one device, or may be distributed and provided in a plurality of devices. The computer system herein includes a microcontroller having one or more processors and one or more memories. Therefore, the microcontroller is also composed of one or more electronic circuits including semiconductor integrated circuits or large-scale integrated circuits.

Furthermore, it is not an essential configuration for the capacitor manufacturing system 100 that multiple functions of the capacitor manufacturing system 100 are concentrated in one housing, and the components of the capacitor manufacturing system 100 are distributed among multiple housings. may be provided. Furthermore, at least some functions of the capacitor manufacturing system 100, for example, some functions of the control unit 411, may be realized by cloud (cloud computing) or the like. Conversely, multiple functions of capacitor manufacturing system 100 may be integrated into one housing.

In a modified example, as shown in FIG. 17, the testing method (withstand voltage test step S13) may further include a re-discharge step ST10. The re-discharge step S10 includes, after the measurement step S2, applying a voltage that increases over time between the pair of electrodes 101, 102 to cause discharge to occur again between the pair of electrodes 101, 102.

In a modified example, the voltage application device 450 shown in FIG. 9 may be used as the withstand voltage testing system 410. In this case, the withstand voltage determination step S3 may be omitted.

(4) Summary As explained above, the testing method according to the first aspect is a testing method for a capacitor element (10) used in a capacitor (1). A capacitor element (10) has a pair of electrodes (101, 102). This inspection method includes a voltage application step (ST1) and a measurement step (ST2). In the voltage application step (ST1), an applied voltage (V0) that increases over time is applied between the pair of electrodes (101, 102) until discharge occurs between the pair of electrodes (101, 102). Including. The measurement step (ST2) includes measuring the applied voltage (V0) when a discharge occurs between the pair of electrodes (101, 102) in the voltage application step (ST1) as a discharge voltage (Vsp).

According to this aspect, there is an advantage that the state of the target capacitor element (10) can be easily managed.

In the inspection method according to the second aspect, in the first aspect, the rate of increase (v _in ) of the applied voltage (V0) is within the range of 0.2 V/ms to 4.0 V/ms.

According to this aspect, it becomes easy to suppress variations in the discharge voltage (Vsp) caused by the rate of increase ( _vin ) in the applied voltage (V0).

In the inspection method according to the third aspect, in the first or second aspect, the voltage application step (ST1) is performed from a pair of constant current sources (CI1) through a switching element (first switch SW1) whose switching is controlled. This includes controlling the rate of increase in the applied voltage (V0) by passing a current through the electrodes (101, 102).

According to this aspect, it becomes possible to appropriately control the rate of increase (v _in ) of the applied voltage (V0).

The inspection method according to the fourth aspect, in any one of the first to third aspects, further includes a withstand voltage determination step (ST4). In the withstand voltage determination step (ST4), after the measurement step (ST2), a voltage equal to or lower than a predetermined determination voltage ( _Vjudge ) is applied between the pair of electrodes (101, 102) to determine the withstand voltage of the capacitor element (10). Including.

According to this aspect, by determining the withstand voltage after discharge, it becomes possible to eliminate capacitor elements (10) that are defective due to discharge, and it becomes possible to improve the quality of the capacitor elements (10).

The inspection method according to the fifth aspect further includes a re-discharge step (ST10) in any one of the first to fourth aspects. In the re-discharge step (ST10), after the measurement step (ST2), a voltage that increases over time is applied between the pair of electrodes (101, 102) to cause a discharge between the pair of electrodes (101, 102) again. Including causing.

According to this aspect, by causing discharge to occur multiple times, it is possible to improve the quality of the capacitor element (10).

In the inspection method according to the sixth aspect, in any one of the first to fifth aspects, in the voltage application step (ST1), the applied voltage (V0) is increased from the initial voltage (Vi) over time. . The initial voltage (Vi) is greater than zero.

According to this aspect, it is possible to shorten the time from the start of application of the applied voltage (V0) to the time when discharge occurs, and it is possible to increase the number of tests per unit time.

The inspection method according to the seventh aspect further includes a recording step (ST3) in any one of the first to sixth aspects. The recording step (ST3) includes recording the discharge voltage (Vsp) measured in the measuring step (ST2) on a recording medium.

According to this aspect, the discharge voltage (Vsp) can be easily managed.

A management method according to an eighth aspect is a management method for a capacitor (1) manufactured by a capacitor manufacturing system (100). The management method includes an inspection process. The testing step includes performing the testing method of any one of the first to seventh aspects on a plurality of capacitor elements (10).

According to this aspect, there is an advantage that the state of the capacitor manufacturing system (100) can be easily managed.

In the management method according to the ninth aspect, in the eighth aspect, the plurality of capacitor elements (10) include the capacitor elements (10) of all the capacitors (1) manufactured by the capacitor manufacturing system (100).

According to this aspect, there is an advantage that the state of the capacitor element (10) manufactured by the capacitor manufacturing system (100) can be easily managed.

The management method according to the tenth aspect further includes a management step in the eighth or ninth aspect. The management step includes managing the states of the plurality of capacitor elements (10) based on the measured discharge voltages (Vsp) of the plurality of capacitor elements (10).

According to this aspect, there is an advantage that the state of the capacitor element (10) manufactured by the capacitor manufacturing system (100) can be easily managed.

In the management method according to the eleventh aspect, in the tenth aspect, the management step includes a classification step and a distribution understanding step. The classification process includes classifying the plurality of capacitor elements (10) into plural capacitor elements (10) each containing two or more capacitor elements (10) based on the manufacturing conditions during the production of the plurality of capacitor elements (10) by the capacitor manufacturing system (100). Includes classification into capacitor element groups. The distribution determining step includes determining, for at least one of the plurality of capacitor element groups, the distribution of discharge voltages of two or more capacitor elements (10) included in the capacitor element group.

According to this aspect, it becomes possible to grasp changes in the manufacturing conditions of the capacitor element (10).

The production method according to the twelfth aspect is the production of a capacitor (1) using the inspection method according to any one of the first to seventh aspects or the management method according to any one of the eighth to eleventh aspects. It's a method.

According to this aspect, there is an advantage that the state of the target capacitor element (10) can be easily managed.

The inspection system (410) according to the thirteenth aspect is an inspection system for a capacitor element (10) used in a capacitor (1). A capacitor element (10) has a pair of electrodes (101, 102). The inspection system (41) includes a voltage application section (412) and a measurement section (413). The voltage application unit (412) applies an applied voltage (V0) that increases over time between the pair of electrodes (101, 102) until discharge occurs between the pair of electrodes (101, 102). . The measurement unit (413) measures the applied voltage (V0) when discharge occurs between the pair of electrodes (101, 102) as the discharge voltage (Vsp).

According to this aspect, there is an advantage that the state of the target capacitor element (10) can be easily managed.

The configurations according to the second to seventh aspects are not essential to the inspection method and can be omitted as appropriate. The configurations according to the ninth to eleventh aspects are not essential to the management method and can be omitted as appropriate.

1 Capacitor 10 Capacitor element 101, 102 Electrode 100 Capacitor manufacturing system 410 Inspection system (withstand voltage inspection system)
412 Voltage application section 413 Measurement section ST1 Voltage application process ST2 Measurement process ST3 Recording process ST4 Withstand voltage judgment process ST10 Re-discharge process V0 Applied voltage Vsp Discharge voltage V _Judge judgment voltage Vi Initial voltage v _in increase rate

Claims (14)

A method for inspecting a capacitor element used in a capacitor, the method comprising:
a voltage application step of applying an applied voltage that increases over time between a pair of electrodes of the capacitor element until a discharge occurs between the pair of electrodes;
a measuring step of measuring the applied voltage as a discharge voltage when the discharge occurs between the pair of electrodes in the voltage application step;
including;
The voltage application step includes controlling the rate of increase in the applied voltage by flowing a current from a constant current source to the pair of electrodes via a switching element whose switching is controlled.
Inspection method. A method for testing a capacitor element used in a capacitor, the method comprising:
a voltage application step of applying an applied voltage that increases over time between a pair of electrodes of the capacitor element until a discharge occurs between the pair of electrodes;
a measuring step of measuring the applied voltage as a discharge voltage when the discharge occurs between the pair of electrodes in the voltage application step;
including;
In the voltage application step, the applied voltage is increased over time from an initial voltage,
the initial voltage is greater than 0V;
Inspection method. The voltage application step includes controlling the rate of increase in the applied voltage by flowing a current from a constant current source to the pair of electrodes via a switching element whose switching is controlled.
The inspection method according to claim 2. The rate of increase of the applied voltage is within the range of 0.2 V/ms to 4.0 V/ms,
The testing method according to any one of claims 1 to 3. After the measuring step, the method further includes a withstand voltage determination step of applying a voltage equal to or lower than a predetermined determination voltage between the pair of electrodes to determine the withstand voltage of the capacitor element.
The testing method according to any one of claims 1 to 4. After the measurement step, the method further includes a re-discharge step of applying a voltage that increases over time between the pair of electrodes to generate discharge again between the pair of electrodes.
The testing method according to any one of claims 1 to 5. further comprising a recording step of recording the discharge voltage measured in the measuring step on a recording medium,
The testing method according to any one of claims 1 to 6. A method for managing capacitors manufactured by a capacitor manufacturing system, the method comprising:
The method includes the step of performing the testing method according to any one of claims 1 to 7 on a plurality of the capacitor elements.
Management method. The plurality of capacitor elements include capacitor elements of all capacitors manufactured by the capacitor manufacturing system.
The management method according to claim 8. further comprising a management step of managing the states of the plurality of capacitor elements based on the measured discharge voltages of the plurality of capacitor elements;
The management method according to claim 8 or 9. The management process is
a classification step of classifying the plurality of capacitor elements into a plurality of capacitor element groups each including two or more capacitor elements, based on manufacturing conditions when the plurality of capacitor elements are manufactured by the capacitor manufacturing system;
For at least one of the plurality of capacitor element groups, a variation management step of managing variations in the discharge voltage of the two or more capacitor elements included in the capacitor element group;
including,
The management method according to claim 10. A method for producing a capacitor, the method comprising:
Using the inspection method according to any one of claims 1 to 7 or the management method according to any one of claims 8 to 11,
Production method. An inspection system for capacitor elements used in capacitors,
a voltage applying unit that applies an applied voltage that increases over time between a pair of electrodes of the capacitor element until discharge occurs between the pair of electrodes;
a measurement unit that measures the applied voltage when discharge occurs between the pair of electrodes as a discharge voltage;
Equipped with
The voltage application unit controls the rate of increase in the applied voltage by flowing a current from a constant current source to the pair of electrodes via a switching element whose switching is controlled.
Inspection system. An inspection system for capacitor elements used in capacitors,
a voltage applying unit that applies an applied voltage that increases over time between a pair of electrodes of the capacitor element until discharge occurs between the pair of electrodes;
a measurement unit that measures the applied voltage when discharge occurs between the pair of electrodes as a discharge voltage;
Equipped with
The voltage application unit increases the applied voltage from an initial voltage over time,
the initial voltage is greater than 0V;
Inspection system.

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