What are the causes of failure of various electronic components?

Date：2022-12-16 14:38:40Views：460

Electronic components mainly include components and devices. Electronic components are finished products whose molecular components are not changed during production and processing, such as capacitors, resistors and inductors. Electronic devices are finished products whose molecular structure changes during the production process, such as electronic tubes, integrated circuits, etc. In order to help you understand deeply, this paper will summarize the relevant knowledge about the failure causes of various electronic components. If you are interested in the content to be covered in this article, please read on.

Resistance components

The failure of resistance components accounts for a large proportion in electronic equipment. Resistance can be divided into shunt, voltage drop, load, impedance matching and other functions. According to different structures, resistance components can be divided into wire wound resistance and non wire wound resistance.

The main failure modes of resistance components include contact damage, open circuit and lead mechanical damage.

The influence of temperature change on the resistance is mainly that when the temperature rises, the thermal noise of the resistance increases, the resistance value deviates from the nominal value, and the allowable dissipation probability decreases. But we can also take advantage of this characteristic of resistance. For example, there are specially designed types of resistance: PTC (positive temperature coefficient thermistor) and NTC (negative temperature coefficient thermistor). Their resistance values are greatly affected by temperature.

Mechanical vibration will loosen welding points and crimping points, resulting in poor contact and other mechanical damage.

Capacitor components

The main failure modes of capacitive components include breakdown, mechanical damage, electrolyte leakage, etc.

The main reasons for capacitor breakdown are:

1. The medium has defects, impurities and conductive ions;

2. Medium aging;

3. The dielectric material has electric and air gap breakdown;

4. The medium is mechanically damaged during manufacturing;

5. The molecular structure of the medium changes;

6. The migration of metal ions constitutes a conducting channel or edge flashover discharge.

The capacitance failure may also be caused by open circuit. The oxidation of the contact point between the outgoing line and the capacitor leads to low level open circuit, the poor contact between the outgoing line and the electrode, and the open circuit fault caused by mechanical breakage of the metal foil led out from the anode of the electrolytic capacitor. Therefore, the capacitor may also fail due to the degradation of electrical parameters, for example, the migration of metal ions in electrode materials, the self healing effect of metallized electrodes, the electrolytic and chemical corrosion of electrodes, moisture, surface pollution, etc. may cause the degradation of electrical parameters of capacitors.

Inductive components

Inductive components involve transformers, inductors, filter coils, oscillating coils, etc. Most of the faults of inductive components are caused by external factors, such as the temperature rise of the transformer, excessive current passing through the coil due to load short circuit, etc., which will cause the coil to have short circuit, short circuit, breakdown and other faults.

In the integrated circuit, no matter which part has problems, the whole cannot operate normally, such as electrode short circuit, open circuit, mechanical wear, poor solderability, etc. Failure mainly includes complete damage and poor thermal stability. Thermal stability failure mainly occurs at high temperature or low temperature, and failure occurs when the device exceeds the operating temperature range.

resolvent

How to effectively find the failed electronic components and replace or repair the problems?

During debugging, the circuit fails to work or works abnormally. First, the dynamic observation method is used to judge the failure of electronic components by listening, looking, touching, smelling and other methods when the line equipment is powered on. For example, listen to whether the equipment has abnormal sound. Look carefully to see whether there is smoke and sparks in the circuit; Feel whether the components and circuits are hot; Smell if there is any smell like burning. It can also be judged by measuring the on-off condition of the circuit with a multimeter and various values in normal and abnormal circuits.

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