Capacitor segmented aging method

Abstract

The invention discloses a segmented aging method of a capacitor, which realizes efficient repair of dielectric defects through segmented voltage / temperature cooperative control, multi-parameter combined screening and repairable capacitor secondary enhancement processing. The comprehensive performance standard of qualified capacitors covers key indexes such as leakage current, ESR, loss angle and the like, experiments show that the qualification rate can reach 98.2%, and the method is suitable for various capacitor types and has remarkable industrial application value.

Description

TECHNICAL FIELD

[0001] The application relates to a capacitor segment aging method. BACKGROUND

[0002] Microscopic defects of a capacitor caused by dielectric impurities, mechanical stress or a capacitor segment aging method fluctuation in a manufacturing process can cause problems such as increased leakage current and decreased withstand voltage performance. A traditional aging technology uses a cathode layer to degrade a defect area by constant voltage and temperature, but the method can only suppress leakage current and cannot repair dielectric defects, such as Figure 2 As shown in the prior art, self-healing of the existing capacitor during the aging process is not repairing the oxide film, but degrading (de-doping or reducing, increasing the polymer resistivity) or decomposing the cathode layer at the position with large leakage current, so as to isolate the cathode layer from the oxide film at the position with large leakage current, thereby reducing the leakage current of the capacitor. The method has the defect that the dielectric defects are not repaired, but are only isolated, which can cause poor aging effect, large leakage current and low capacitor qualification rate. SUMMARY

[0003] To solve the above technical problems, the application provides a capacitor segment aging method.

[0004] The application is achieved by the following technical solutions.

[0005] The application provides a capacitor segment aging method, which comprises the following steps:

[0006] (1) placing the capacitor in a 60 DEG C to 95 DEG C, 60% RH to 95% RH environment for pretreatment for 6 to 60 hours;

[0007] (2) sequentially increasing the voltage of the pretreated capacitor to a target voltage at a first segment voltage increasing rate of 0.1 V / min, a second segment voltage increasing rate of 0.3 V / min and a third segment voltage increasing rate of 0.1 V / min;

[0008] (3) maintaining the constant voltage for 30 to 60 min after reaching the target voltage, increasing the temperature to an intermediate temperature at a rate of 4 to 7 DEG C / min, and then increasing the temperature to a final temperature at a rate of 2 to 4 DEG C / min, and maintaining for 60 to 300 min;

[0009] (4) screening the aged capacitor.

[0010] The target voltage is 100% to 150% of the rated voltage of the capacitor.

[0011] The voltage increasing step of the target voltage is:

[0012] The first segment is increased from 0 V to 20% of the rated voltage at a rate of 0.10 V / min;

[0013] The second section is from 20% to 80% of the rated voltage at a rate of 0.3V / min;

[0014] The third section is from 80% to 100%-120% of the rated voltage at a rate of 0.1V / min.

[0015] The intermediate temperature is 60-105℃, and the final temperature is 100-150℃.

[0016] Deionized water vapor is used as the humidity source in the pretreatment environment.

[0017] The screening step of the aged capacitor is:

[0018] (1) detecting the leakage current, capacitance deviation, ESR and insulation resistance of the aged capacitor;

[0019] (2) classifying the capacitor into qualified, repairable and unrepairable according to the detection results;

[0020] (3) performing secondary treatment on the repairable capacitor, and pretreating it again for 6-48 hours.

[0021] The judgment conditions of the repairable capacitor are: leakage current (μA)≤rated voltage (V)*capacity (μF), capacitance deviation≤±20%, ESR≤200% of the nominal value, and loss≤6%.

[0022] The amplitude of the alternating current pulse is 3%-10% of the rated voltage, and the duty cycle is 10%-30%.

[0023] The aged capacitor is considered qualified if it meets the following parameters:

[0024] Leakage current≤rated voltage (V)*capacity (μF)*0.1;

[0025] Capacitance deviation≤±20%;

[0026] ESR≤% of the nominal value;

[0027] Loss tangent≤0.06;

[0028] The test frequency of the capacitance and loss tangent is (100±5)Hz, the withstand voltage test duration is 120 seconds, and the test frequency of the ESR is (100±5)kHz.

[0029] The present application has the beneficial effects of solving the dielectric defects in the capacitor in principle and providing an efficient and feasible operation method. The dielectric defects in the capacitor can be repaired by using the present application, the leakage current of the capacitor is reduced, and the product qualification rate is improved. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 Schematic diagram of self-healing principle of the present application; Figure 2 Schematic diagram of self-healing principle of the prior art; Figure 3 Schematic diagram of capacitor defect. DETAILED DESCRIPTION

[0032] The technical solutions of the present application are described further below, but the scope of protection claimed is not limited to the description.

[0033] A capacitor segmented aging method, comprising the following steps:

[0034] Pre-treatment stage:

[0035] Place the capacitor in an environment of 60-95℃ and 60-95% RH for 6-60 hours, so that water vapor penetrates into the dielectric defect area.

[0036] Segmented power-up:

[0037] Stage 1 (0.1 V / min): from 0 V to 20% of the rated voltage, slowly rising to avoid defect expansion;

[0038] Stage 2 (0.3 V / min): to 80% of the rated voltage, accelerating the oxidation reaction (AL+H2O→AL2O3);

[0039] Stage 3 (0.1 V / min): to 100-120% of the rated voltage, stabilizing the repair layer structure;

[0040] Stage 4 (constant voltage): maintain the voltage for 0-60 minutes to ensure complete reaction.

[0041] Segmented temperature rise:

[0042] Stage A (5℃ / min): quickly rise to intermediate temperature (e.g. 75℃), activate reaction kinetics;

[0043] Stage B (2℃ / min): slowly rise to final temperature (e.g. 125℃), prevent thermal stress from damaging the repair layer.

[0044] Intelligent screening and repair process

[0045] Screening criteria:

[0046]

[0047]

[0048] Repairable capacitor secondary treatment:

[0049] Enhanced pre-treatment: humidity raised to 80%RH~95%RH, time 6~60 hours;

[0050] Adjustment of power-up parameters: stage 2 ramp rate reduced to 0.2V / min, constant voltage time extended to 60 minutes;

[0051] Auxiliary pulse electric field: superimposed 1~5kHz AC pulse (amplitude 3%~10% rated voltage), to promote ion migration and oxide film densification.

[0052] Qualified capacitor comprehensive performance standards

[0053] Leakage current ≤ rated voltage (V) * capacity (μF) * 0.1;

[0054] Capacitance deviation ≤ ± 20%;

[0055] ESR ≤ nominal value %;

[0056] Loss tangent ≤ 0.06;

[0057] Reliability:

[0058] Voltage resistance: 1.5 times rated voltage for 60 seconds without breakdown;

[0059] Lifetime: capacitance attenuation ≤ 20% after 125℃ / 2000 hours.

[0060] Example 1: Aluminum electrolytic capacitor aging and repair

[0061] Aging conditions:

[0062] Pre-treatment: 85℃, 85%RH, 12 hours;

[0063] Stepwise power-up: 0→5V (0.1V / min), 5→20V (0.3V / min), 20→25V (0.1V / min), constant voltage 25V for 200 minutes;

[0064] Stepwise temperature rise: 25→85℃ (5℃ / min), 85→105℃ (2℃ / min).

[0065] Screening results:

[0066] Qualified capacitors: 980 / 1000 (98%);

[0067] Repairable capacitors: 15 (I_L=117.5~1175μA, ΔC=-20%~+20%);

[0068] Non-repairable capacitors: 5 (I_L>1175μA, ΔC>±25%).

[0069] Secondary repair:

[0070] Preconditioning: 90°C, 95%RH, 36 hours;

[0071] Power-up adjustment: Stage 2 ramp rate 0.2V / min, constant voltage time 60 minutes;

[0072] Superimposed 3kHz AC pulse (amplitude 5%).

[0073] Repair result: 12 qualified, success rate 80%.

[0074] Example 2: Tantalum electrolytic capacitor extended application

[0075] Burn-in condition adaptation:

[0076] Preconditioning: 70°C, 75%RH, 18 hours;

[0077] Segmented power-up: 0→10V (0.1V / min), 10→30V (0.2V / min), constant voltage 30V 200 minutes;

[0078] Segmented temperature rise: 25→60°C (3°C / min), 60→85°C (1°C / min).

[0079] Effect:

[0080] Qualified rate 95.6% (average leakage current 2.8μA); verified the universality of the method.

Claims

1. A method of capacitor burn-in segmentation, comprising: The method comprises the following steps: (1) Pre-treat the capacitor in an environment of 60-95℃ and 60-95% RH for 6-60 hours; (2) Increase the voltage of the pre-treated capacitor to the target voltage at a first voltage increasing rate of 0.1 V / min, a second voltage increasing rate of 0.3 V / min and a third voltage increasing rate of 0.1 V / min; (3) After reaching the target voltage, maintain the voltage for 0-60 min, then increase the temperature to the intermediate temperature at a rate of 4-7℃ / min, and then increase the temperature to the final temperature at a rate of 2-4℃ / min, and maintain the temperature for 60-300 min; (4) Screen the aged capacitor.

2. The method of claim 1, wherein: The target voltage is 100-150% of the rated voltage of the capacitor.

3. The method of claim 2, wherein: The voltage increasing step of the target voltage is: First segment: increase the voltage from 0 V to 50% of the rated voltage at a rate of 0.10 V / min; Second segment: increase the voltage from 50% to 80% of the rated voltage at a rate of 0.30 V / min; Third segment: increase the voltage from 80% to 100-150% of the rated voltage at a rate of 0.10 V / min.

4. The method of claim 1, wherein: The intermediate temperature is 60-105℃, and the final temperature is 100-150℃.

5. The method of claim 1, wherein: Deionized water vapor is used as the humidity source in the pre-treatment environment.

6. The method of claim 1, wherein: The screening step of the aged capacitor is: (1) Detect the leakage current, capacity, ESR and loss of the aged capacitor; (2) According to the detection results, divide the capacitor into qualified, repairable and unrepairable; (3) Perform secondary treatment on the repairable capacitor, and pre-treat it again for 6-48 hours.

7. The method of claim 6, wherein: The judgment conditions of the repairable capacitor are: leakage current (μA) ≤ rated voltage (V) * capacity (μF), capacity deviation ≤ ±20%, ESR ≤ 200% of the nominal value, and loss ≤ 6%.

8. The method of claim 6, wherein: the first and second voltages are applied to the capacitor for a first period of time; and the third and fourth voltages are applied to the capacitor for a second period of time. The aged capacitor is considered qualified if it meets the following parameters: Leakage current ≤ rated voltage (V) * capacity (μF) * 0.1; Capacity deviation ≤ ±20%; ESR ≤ nominal value; Loss tangent ≤ 0.

06.

9. The method of claim 9, wherein: The test frequency of the capacity and loss tangent is (100±5) Hz, the voltage resistance test duration is 120 seconds, and the test frequency of the ESR is (100±5) kHz.

Images