Quality Inspection at Hongda Capacitors

2024-01-16

Improving product quality is the eternal pursuit of enterprises.

Hongda Capacitors strictly controls product quality. Both raw materials and products need to be strictly controlled and strictly follow the company's quality management requirements.

Establish a quality management system that complies with national standards to ensure the stability and reliability of product/service quality. Help customers improve product quality, thereby enhancing competitiveness and brand value, and achieving sustainable development.

QA inspectors authenticate tantalum Capacitors based on these specifications.

* Test environment condition

* Testing process

* Capacitance C and loss tangent (DF)

* Equivalent Series Resistance (ESR)

* DC leakage current (DCL)

1. Test environment condition

Environment temperature: 25±2℃

relative humidity: ≤70%RH

2. Testing process

"Capacitance (C) and loss tangent value (DF)" → "Equivalent series resistance (ESR)" → "DC leakage current (DCL)"

3. Capacitance C and loss tangent (DF)

3.1. Test Method

1. When the nominal capacitance is ≥1μF, select the "series (Cs)" test method;
2. When the nominal capacitance is <1μF, select the "parallel connection (Cp)" test method.

3.2. Test Conditions

1. Test frequency: 120Hz
2. Apply forward polarization voltage: Apply 2.2V forward polarization voltage to the tantalum capacitor under test. Otherwise, the polarization of the tantalum capacitor will not be completed and the test error will be too large.

3.3. Wire connection requirements

The length of the connecting wire between the test port and the tantalum capacitor should be as short as possible, no more than 40cm. If the wire is too long, it will affect the test results of the loss tangent value;

During testing, the "H" terminal of the instrument test port is connected to the positive pin of the tantalum capacitor, and the "L" terminal is connected to the negative pin of the tantalum capacitor.

Calibration and clearing should be performed before testing.

The wires connecting the positive electrode of the capacitor are uniformly insulated in red, and the negative wire is black to prevent unintentional reverse connection during testing;

4. Equivalent Series Resistance (ESR)

4.1. The test fixture uses a special fixture, and the length of the connecting wire between the test port of the instrument and the pin of the tantalum capacitor does not exceed 5cm.

4.2. Select "100KHz" for the test frequency.

4.3. Apply a forward polarization voltage of 2.2V to the tantalum capacitor under test. Otherwise, the polarization of the tantalum capacitor will not be completed and the test error will be too large.

4.4. Calibration and clearing should be performed before testing.

5. DC leakage current (DCL)

5.1. The charging current of the measuring instrument is <150mA.

5.2. When tantalum capacitors with different voltages need to be measured continuously, the measurement should start from the low-voltage tantalum capacitor.

5.3. The measured voltage should be consistent with the rated voltage of the tantalum capacitor.

5.4. After the test, the capacitor should be discharged with a 1KΩ resistor for 5 to 20 seconds. After the resistor is discharged, short-circuit discharge should be performed. After the discharge is completed, the residual voltage of the tantalum capacitor should be <0.5V.

6. Test instruments recommended by our company

LCR digital bridge: Manufacturer (KEYSIGHT), model E4980AL, measures capacitance C, loss tangent value DF, equivalent series resistance ESR;

Leakage current test: manufacturer (TONGHUI), model TH2689A, measures DC leakage current value DCL.