JP4115456B2 - Measuring device for solid electrolytic capacitors - Google Patents

Description

  The present invention relates to an apparatus for measuring ESR and ESL of a solid electrolytic capacitor.

Conventionally, a chip-type solid electrolytic capacitor shown in FIG. 14 is known (see, for example, Patent Document 1).
As shown in FIG. 14, the solid electrolytic capacitor (1) includes a capacitor element (2) to which lead frames (9) and (90) are attached, and the capacitor element (2) is made of a synthetic resin housing (70). Covered with. The lead frames (9) and (90) are bent along the housing (70) and exposed from the side surface and the lower surface of the housing (70). In the capacitor element (2), a dielectric oxide film (21) is formed on a part of an anode body (20) made of a valve metal, and a cathode layer (3), carbon is formed on the dielectric oxide film (21). A layer (6) and a silver paste layer (60) are provided in this order. That is, the portion where the dielectric oxide film (21) is formed on the anode body (20) is the cathode (2b), and the portion where the dielectric oxide film (21) is not formed on the anode body (20) is the anode (2a). It becomes.
Here, the valve metal refers to a metal on which an extremely dense and durable dielectric oxide film is formed by electrolytic oxidation treatment. Al (aluminum), Ta (tantalum), Ti (titanium), Nb (niobium) Etc.

ESR (equivalent series resistance) is known as an important electrical characteristic of the capacitor (1). In recent years, such a capacitor (1) is often incorporated into a high-frequency circuit of several MHz or more, and the higher the frequency, the larger the impedance. Therefore, the ESL (equivalent series inductance) is also small. It has electrical characteristics.
For example, in order to measure the ESR and ESL of the capacitor (1) shown in FIG. 14 using the four-terminal method, the wire (80) ( The first probes (81) and (81) and the second probes (82) and (82) connected through 80) are applied. The first probe (81) (81) is divided into a high potential side input probe and a high potential side output probe, and the second probe (82) (82) is a low potential side input probe and a low potential side output. Separated into probes. A constant voltage, specifically 0.5V sine wave is passed from the high potential side input probe to the low potential side input probe from the measuring instrument (8), and the ammeter connected in series to both input probes and both output probes The ESR and ESL of the capacitor (1) are measured from the measured value and phase shift with a voltmeter connected in series.
When measuring the ESR and ESL of the capacitor (1), the impedance based on the resistance, inductance and capacitance in the measuring instrument (8) including the probes (81) and (82), and the probes (81) and (82) It is necessary to correct the contact resistance of the capacitor (1), and the correction includes the following open correction and short correction.

The impedance component in the measuring instrument (8) includes residual impedance and floating admittance. The floating admittance is measured by open correction data measurement, and the residual impedance is measured by short correction data measurement. When the probes (81) and (82) shown in FIG. 15 are in an open state, the residual impedance can be ignored, so that the floating admittance (mainly stray capacitance) can be measured, and the probes (81) and (82) shown in FIG. In the state, stray admittance is bypassed, so the residual impedance can be measured. The measured value of the capacitor (1) is corrected based on the measured data for open correction and the measured data for short correction. These corrections are called open correction and short correction, respectively.
As shown in FIG. 15, open correction data measurement when measuring ESR and ESL using the four-terminal method is a small metal piece (45) as a jig on the first probe (81) (81). Hit. In addition, with the same small metal piece (45) applied to the second probe (82) (82), a 0.5V sine wave is applied, and the impedance based on the resistance, inductance, and capacitance is measured. Store in the container (8).
In the short correction data measurement, as shown in FIG. 16, two first probes (81) to be in contact with one lead frame (90) on one side of a large metal piece (46) as a jig. ) (81) to fix. Two second probes (82) and (82) to be in contact with the other lead frame (9) are horizontally moved from the side and applied to the opposite side surface of the large metal piece (46). Thereafter, a 0.5 V sine wave is energized, and the impedance based on the resistance value, inductance, and capacitance at this time is stored in the measuring instrument (8).
In the short correction data measurement, in addition to the residual impedance, the contact resistance between the probe (81) (82) and the large metal piece (46) can be measured. However, in the four-terminal method, the contact resistance is a value obtained by adding the impedance based on the stray capacitance between the probes to the actual contact resistance.
The data measurement for both corrections is performed, for example, with only open correction, the residual impedance and the contact resistance cannot be corrected, and only the floating admittance is corrected. On the contrary, since the floating admittance cannot be measured only by the short correction, both the short correction and the open correction are necessary to accurately measure the ESR and ESL of the capacitor (1).
When measuring the ESR and ESL of the actual capacitor (1), a value obtained by subtracting the impedance based on the resistance value, the inductance, and the capacitance obtained by the data measurement for the short correction and the open correction from the measurement value is obtained.

JP 2002-246268 A

In the conventional method, the first probe (81) and the second probe (82) are moved horizontally during open correction data measurement. Therefore, when ESR and ESL of capacitors with different lateral dimensions are measured continuously, the stray admittance (especially stray capacitance between the first probe (81) and the second probe (82)) slightly changes and is accurately measured. I discovered that data for open correction cannot be measured.
When measurement is performed using the four-terminal method, the second probes (82) and (82) are moved horizontally during short correction data measurement and capacitor measurement, as shown in FIG. Therefore, the stray capacitance between the second probes (82) and (82) slightly changes. As a result, an error occurs between the current passing through the large metal piece (46) and its phase angle, and the current passing through the capacitor (1) and its phase angle. Therefore, an error also occurs in the impedance to be corrected in the short correction. This problem is particularly serious in the high frequency region.
An object of the present invention is to provide a measuring apparatus capable of accurate open correction and short circuit correction.

A measuring device for a capacitor (1) in which at least the lower surfaces of the anode side and cathode side lead frames (9) and (90) are exposed from a housing (70),
  On the measuring device body (5), a first electrode (51) and a second electrode (52) to be in contact with the lower surface of each lead frame (9) (90) are fixed in the same plane,
  When measuring data for short correction, the same jig is in contact with and electrically connected to the first electrode (51) and the second electrode (52),
In the measuring device main body (5), a first correction value used for open correction in which the first electrodes (51) (51) or the second electrodes (52) (52) are electrically connected, and A memory (40) for storing a second correction value used for short correction in which all of the first electrodes (51) (51) and the second electrodes (52) (52) are electrically connected, and a capacitor (1 In the measuring device of the capacitor (1) provided with the arithmetic circuit (4) for subtracting the impedance based on the first correction value and the second correction value from the measurement value at the time of measurement of
The first electrode (51) and the second electrode (52) each have an inclined surface (57) inclined downward toward the inside, and the first electrode (51) and the second electrode (52) It has a flat surface that is substantially parallel to the lower surface and is connected to the downwardly inclined slope (57).
On the first electrode (51) and the second electrode (52), protrusions (56) and (56) are formed which are in contact with the lower surfaces of the anode side and cathode side lead frames (9) and (90), and A flat surface is formed substantially parallel to the lower surfaces of the first electrode (51) and the second electrode (52) and connected to the protrusions (56) and (56).

Data measurement for open correction When measuring data for open correction , a small metal piece (45) as a jig is placed across the first electrode (51) (51) or the second electrode (52) (52), The first electrodes (51) (51) or the second electrodes (52) (52) are electrically connected to each other. The impedance based on the resistance, inductance, and capacitance obtained at this time is stored in the memory (40) as the first correction value.
Data measurement for short correction When measuring data for short correction , a large metal piece (46), which is a jig, is straddled across all of the first electrode (51) (51) and the second electrode (52) (52). The first electrodes 51 and 51 and the second electrodes 52 and 52 are all electrically connected. The impedance based on the resistance, inductance, and capacitance obtained at this time is stored in the memory (40) as the second correction value.
Open correction and short correction at the time of measurement The capacitor (1) is placed across the first electrode (51) (51) and the second electrode (52) (52). One lead frame (90) is placed across the first electrodes (51) (51), and the other lead frame (9) is placed across the second electrodes (52) (52). The arithmetic circuit (4) calculates the impedance of the first electrode, the second electrode (51) (52), and both electrodes (51) from the first correction value and the second correction value stored in the memory (40). The impedance based on the contact resistance between (52) and the capacitor (1) is calculated, and the value obtained by subtracting each impedance from the measured value is obtained. Correction for subtracting impedance based on the first correction value is open correction, and correction for subtracting impedance based on the second correction value is short correction.
Since the first electrode (51) (51) and the second electrode (52) (52) are fixed on the device body (5), the capacitor (1) having different lateral dimensions is continuously measured. In addition, the impedance based on the stray capacitance between the first electrode (51) and the second electrode (52) does not change. Thus, accurate open correction can be performed.
Further, since the first electrodes (51) (51) and the second electrodes (52) (52) are fixed on the apparatus body (5), the first electrodes (51) (51) and the second electrodes The stray capacitance between the electrodes (52) and (52) is constant. As a result, it is possible to eliminate an error in contact resistance between the measurement of the large metal piece (46) and the measurement of the capacitor, and an accurate short circuit correction is possible.

(First embodiment)
Hereinafter, an example of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a perspective view of a measuring apparatus according to this example. The capacitor (1) to be measured is the same as the conventional one shown in FIG. A base (50) provided on the apparatus main body (5) is provided with a pair of first electrodes (51) (51) and second electrodes (52) (52), and the first electrodes (51) ( 51) is in contact with the cathode side lead frame (90), and the second electrodes (52) and (52) are in contact with the anode side lead frame (9). The first electrodes (51) and (51) and the second electrodes (52) and (52) are parallel to each other, and the longitudinal direction is directed sideways.
The first and second electrodes (51) and (52) are biased upward by a spring (54), and above the capacitor (1) are pressing pieces that bias the capacitor (1) toward the spring (54). (53) is provided. With the pressing piece (53), the capacitor (1) as a measurement object is securely brought into contact with the first and second electrodes (51) and (52), and the capacitor (1) and the first and second electrodes (51) are contacted. This prevents the contact resistance with (52) from varying.
The first and second electrodes (51) and (52) are connected to an arithmetic circuit (4) provided in the apparatus body (5), and the arithmetic circuit (4) includes a memory (40). The memory 40 stores a first correction value and a second correction value obtained during open correction data measurement and short correction data measurement described later. A display window (55) is provided on the front surface of the apparatus body (5), and the display window (55) is connected to the arithmetic circuit (4) to display measurement data.

The first and second electrodes 51 and 52 themselves have a resistance value and an inductance. Also, between the first and second electrodes (51) (51) (52) (52) in contact with the same lead frame (9) (90), and between the first electrode (51) and the second electrode (52) facing each other. Has stray capacitance. Further, there is a resistance in the measuring instrument (8) including the first and second electrodes (51) and (52) and a contact resistance of the capacitor (1).
When accurately measuring the ESR and ESL of the capacitor (1), it is necessary to subtract the impedance received from the resistance, inductance and capacitance of the first and second electrodes (51) and (52), and the parameters to be subtracted are obtained. As methods, there are open correction data measurement and short correction data measurement as in the prior art. The procedure for open correction data measurement and short correction data measurement is shown below.

Data measurement for open correction When measuring data for open correction , a small metal piece (45) as a jig is placed across the first electrode (51) (51) or the second electrode (52) (52), The first electrodes (51) (51) or the second electrodes (52) (52) are electrically connected to each other. The impedance based on the resistance, inductance, and capacitance obtained at this time is stored in the memory (40) as the first correction value.
When data measurements data measurements SHORT compensation for short correction is across all of the first electrode (51) (51) and a second electrode (52) (52), a jig large metal piece (46) The first electrodes 51 and 51 and the second electrodes 52 and 52 are all electrically connected. The impedance based on the resistance, inductance, and capacitance obtained at this time is stored in the memory (40) as the second correction value.
Open correction and short correction at the time of measurement The capacitor (1) is placed across the first electrode (51) (51) and the second electrode (52) (52). One lead frame (90) is placed across the first electrodes (51) (51), and the other lead frame (9) is placed across the second electrodes (52) (52). The arithmetic circuit (4) calculates the impedance of the first electrode, the second electrode (51) (52), and both electrodes (51) from the first correction value and the second correction value stored in the memory (40). The impedance based on the contact resistance between (52) and the capacitor (1) is calculated, and the value obtained by subtracting each impedance from the measured value is obtained. Correction for subtracting impedance based on the first correction value is open correction, and correction for subtracting impedance based on the second correction value is short correction.

Since the first electrode (51) (51) and the second electrode (52) (52) are fixed on the device body (5), the capacitor (1) having different lateral dimensions is continuously measured. In addition, the impedance based on the stray capacitance between the first electrode (51) and the second electrode (52) does not change. Thus, accurate open correction can be performed.
Further, since the first electrodes (51) (51) and the second electrodes (52) (52) are fixed on the apparatus body (5), the first electrodes (51) (51) and the second electrodes The stray capacitance between the electrodes (52) and (52) is constant. As a result, it is possible to eliminate an error in contact resistance between the measurement of the large metal piece (46) and the measurement of the capacitor, and an accurate short circuit correction is possible.
That is, in the past, when measuring using the four-terminal method, as shown in FIG. 16, the second probes (82) and (82) are moved horizontally during short correction data measurement and capacitor measurement. ing. Therefore, the stray capacitance between the second probes (82) and (82) slightly changes. As a result, an error occurs between the current passing through the large metal piece (46) and its phase angle, and the current passing through the capacitor (1) and its phase angle. Therefore, an error also occurs in the impedance to be corrected in the short correction. In particular, in the high-frequency region, this problem becomes large, and nH order ESL cannot be accurately measured.
However, in this example, since the stray capacitance between the first electrodes (51) and (51) and between the second electrodes (52) and (52) is constant, a conventional contact resistance error occurs. Impedance does not change. Further, even when the width of the large metal piece (46) used for measuring the short correction data and the width of the capacitor are different, the contact resistance is constant.

FIG. 4 is a front view of FIG. A loop inductance L1 is generated between the first electrode (51) and the second electrode (52) facing each other when energized. The applicant has conceived that the distance P between the first electrode (51) and the second electrode (52) is 1 mm or less in order to minimize the influence of the loop inductance L1.
As shown in FIGS. 2 and 3, the first electrode 51 and the second electrode 52 are arranged in the arrangement direction of the cathode lead frame 90 and the anode lead frame 9 of the capacitor 1, that is, It extends in the lateral direction.
The lateral length of the first electrode (51) and the second electrode (52) is larger than the interval P between the first electrode (51) and the second electrode (52), so that the capacitor (1) having a long lateral dimension is stable. Can be measured.
The lateral length of the first electrode (51) and the second electrode (52) may be larger than the interval P. Therefore, as shown in FIG. 5, the first electrode 51 and the second electrode 52 may be elliptical or may be arranged radially as shown in FIG.

In view of miniaturization, the capacitor (1) is provided with a lead frame (9) (90) in a flat plate shape as shown in FIG. 7, and the lower surface of the capacitor element (2) and the lower surface of the housing (70). There is also a thing which made it approach.
In addition, the applicant has previously proposed a capacitor (1) in which two portions K and K1 of the cathode side lead frame (90) are exposed as shown in FIG. As shown in FIGS. 7 and 8, the measuring apparatus of this example is useful even in the capacitor (1) in which the lead frames (9) and (90) are exposed from the lower surface of the housing (70).
In this example, two first electrodes (51) (51) and two second electrodes (52) (52) are provided, but three or more may be provided.

(Second embodiment)
In the capacitor (1) shown in FIG. 14, the lower ends of the lead frames (9) and (90) are bent inward. Therefore, as shown in FIG. 9, the lead frames (9) and (90) may be lifted at the bent portions of the lead frames (9) and (90). In this case, when the capacitor (1) is inspected, the first electrode (51) and the second electrode (52) do not come into contact with the lead frames (9) and (90), so that the measurement cannot be performed correctly.
In view of this point, the applicant provided slopes (57) inclined downward toward the inside on the first electrode (51) and the second electrode (52), respectively, as shown in FIG. The inner end of the slope (57) is connected to the flat surface (58).
As shown in FIG. 10, when the capacitor (1) with the lead frame (9) (90) floating is placed on the first electrode (51) and the second electrode (52), the lead frame (9) (90) Since the bent portion C is in contact with the inclined surface (57), ESR and ESL can be measured accurately.
Note that a jig (75) shown in FIG. 11 (a) is used in order to perform open correction data measurement with a measuring apparatus including the first electrode (51) and the second electrode (52). In this structure, small metal pieces (45) and (45) placed on the flat surface (58) are attached to both sides of the lower surface of the insulator (76), and the small metal pieces (45) are the first electrodes (51). (51) The second electrodes (52) and (52) are electrically connected to each other.
Further, in order to perform short correction data measurement, a jig (75a) shown in FIG. 11B is used. In this structure, a large metal piece (46) is attached to the lower surface of the insulator (76). The large metal piece (45) is placed on the flat surface (58) and all of the first electrodes (51) are mounted. ) (45) and the second electrode (52) (52) are electrically connected.

(Third embodiment)
FIG. 12 is a front view of a first electrode (51) and a second electrode (52) for an apparatus for measuring the capacitor (1) with the lead frame (9) (90) exposed from the lower surface shown in FIG. On the first electrode (51) and the second electrode (52), protrusions (56) and (56) are formed in contact with the lower surfaces of the lead frames (9) and (90).
As shown by the solid line in FIG. 12, in order to measure the ESR and ESL of the horizontally long capacitor (1), the lead frames (9) and (90) are applied to the protrusions (56) and (56). In order to measure the capacitor (1) having a short width, the lead frame (9) (90) may be applied to the first electrode (51) and the second electrode (52) out of the protrusion (56). The position of the protrusion (56) is not limited to the end of each electrode (51) (52), as shown in FIG.

(Fourth embodiment)
FIG. 13 is a front view of a first electrode (51) and a second electrode (52) for an apparatus for measuring the capacitor (1) with the two exposed portions K and K1 of the cathode side lead frame (90) shown in FIG. FIG. On the first electrode (51) and the second electrode (52), protrusions (56) and (56) that are in contact with the lower surface of the lead frame (9) and (90) are formed. The first electrode (51) in contact therewith is provided so as to be adjustable left and right. However, the first electrode (51) is fixed with screws (not shown) or the like after being adjusted left and right. This is because if the first electrode (51) remains movable to the left and right, the stray capacitance between the first electrodes (51) and (51) may change as in the prior art.
By making the first electrode (51) adjustable to the left and right, the protrusion (56) can contact both K and K1 of the cathode side lead frame (90), which is convenient for measurement.

  The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope thereof. In addition, the configuration of each part of the present invention is not limited to the above-described embodiment, and various modifications can be made within the technical scope described in the claims.

It is a perspective view of the measuring apparatus concerning this example. It is a top view which shows the data measurement for open correction | amendment. It is a top view which shows data measurement for short correction. It is a front view of FIG. It is a top view of another 1st electrode and the 2nd electrode. It is a top view of another 1st electrode and the 2nd electrode. It is sectional drawing of another conventional solid electrolytic capacitor. It is sectional drawing of another conventional solid electrolytic capacitor. It is a front view of the capacitor where the lead frame is lifted. It is a front view of the 1st electrode and 2nd electrode in other examples. (a) is a front view showing open correction data measurement, and (b) is a front view showing short correction data measurement. It is a front view of the 1st electrode and 2nd electrode for apparatuses which measure the capacitor which a lead frame exposed from the lower surface. It is a front view of the 1st electrode and 2nd electrode for apparatuses which measure the capacitor which exposed two places of the cathode side lead frame. It is sectional drawing of the conventional solid electrolytic capacitor, and a perspective view of a measuring device. It is a front view which shows the conventional data measurement for open correction | amendment. It is a front view which shows the conventional data measurement for short correction. It is a front view which shows the state which measures a capacitor | condenser with a small horizontal dimension after measuring data for short correction with a large metal piece.

Explanation of symbols

(1) Solid electrolytic capacitor
(4) Arithmetic circuit
(5) Device body
(9) Lead frame
(40) Memory
(51) First electrode
(52) Second electrode
(53) Pressing piece
(70) Housing
(90) Lead frame

Claims (2)

A measuring device for a capacitor (1) in which at least the lower surfaces of an anode side and cathode side lead frames (9), (90) are exposed from a housing (70),
A first electrode (51) and a second electrode (52) to be in contact with the lower surfaces of the lead frames (9) and (90) are provided on the measuring device main body (5) in the same plane,
When measuring data for short correction, the first jig (51) and the second electrode (52) are in contact with and electrically connected to the same electrode,
In the measuring device body (5), a first correction value used for open correction in which the first electrodes (51) (51) or the second electrodes (52) (52) are electrically connected, A memory (40) for storing a second correction value used at the time of short correction in which all of the first electrodes (51) (51) and the second electrodes (52) (52) are electrically connected, and a capacitor (1 In the measuring device of the capacitor (1) provided with the arithmetic circuit (4) for subtracting the impedance based on the first correction value and the second correction value from the measurement value at the time of measurement of
The first electrode (51) and the second electrode (52) each have an inclined surface (57) inclined downward toward the inside, and the first electrode (51) and the second electrode (52) An apparatus for measuring a capacitor, characterized by having a flat surface substantially parallel to the lower surface and connected to the inclined surface (57) inclined downward . A measuring device for a capacitor (1) in which at least the lower surfaces of an anode side and cathode side lead frames (9), (90) are exposed from a housing (70),
A first electrode (51) and a second electrode (52) to be in contact with the lower surfaces of the lead frames (9) and (90) are provided on the measuring device main body (5) in the same plane,
When measuring data for short correction, the first jig (51) and the second electrode (52) are in contact with and electrically connected to the same electrode,
In the measuring device body (5), a first correction value used for open correction in which the first electrodes (51) (51) or the second electrodes (52) (52) are electrically connected, A memory (40) for storing a second correction value used at the time of short correction in which all of the first electrodes (51) (51) and the second electrodes (52) (52) are electrically connected, and a capacitor (1 In the measuring device of the capacitor (1) provided with the arithmetic circuit (4) for subtracting the impedance based on the first correction value and the second correction value from the measurement value at the time of measurement of
It said first electrode (51) to the second electrode (52) on the projections in contact with the lower surface of the anode-side and cathode-side lead frame (9) (90) (56) (56) is formed, and the second An apparatus for measuring a capacitor, characterized in that a flat surface is formed substantially parallel to the lower surfaces of the first electrode (51) and the second electrode (52) and connected to the projections (56), (56) .

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