Failure detection of some common electronic components

Date：2022-01-07 11:56:00Views：1083

A large number of various types of electronic components are used in electronic equipment. Most of the equipment failures are caused by the failure or damage of electronic components. Failure analysis plays an important role in ensuring and improving the reliability and quality of products. Failure analysis needs to be introduced in product R & D, production and use. The following are some relevant contents of failure detection and sorting of common electronic components for your reference.

Electronic components mainly include components and devices. Electronic components are finished products whose molecular components are not changed during production and processing, such as capacitance, resistance and inductance. Electronic devices are finished products with changes in molecular structure during generation and processing, such as electron tubes, integrated circuits, etc.

Resistance components

The failure of resistance components accounts for a large proportion in electronic equipment. Resistance can be divided into shunt, step-down, 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 are contact damage, open circuit and mechanical damage of leads. The influence of temperature change on the resistance is mainly that when the temperature increases, the thermal noise of the resistance increases, the resistance deviates from the nominal value, and the allowable dissipation probability decreases. However, we can also use this characteristic of resistance. For example, there are a kind of specially designed resistance: PTC (positive temperature coefficient thermistor) and NTC (negative temperature coefficient thermistor). Their resistance value is greatly affected by temperature. Mechanical vibration will loosen the solder joint and crimping point, resulting in mechanical damage such as poor contact.

Capacitive components

The common failure modes of capacitors mainly include breakdown, open circuit, parameter degradation, electrolyte leakage and mechanical damage. Among them, breakdown is a common failure mode. The main causes of breakdown are as follows: 1) there are defects, defects, impurities or conductive ions in the medium; 2) Aging of media materials; 3) Metal ions migrate to form conductive channel or edge flashover discharge; 4) Air gap breakdown or dielectric breakdown in dielectric materials; 5) Mechanical damage of medium during manufacturing; 6) The change of molecular structure of dielectric materials. Capacitors are very prone to Breakdown Failure in use, resulting in damage.

Open circuit is also a common fault leading to capacitor failure. The oxidation of the contact point between the outgoing line and the electrode will cause low-level open circuit, poor contact or insulation between the outgoing line and the electrode, drying or freezing of the working electrolyte, open circuit caused by corrosion or mechanical fracture of the metal foil from the anode of electrolytic capacitor, instantaneous open circuit between the working electrolyte and dielectric under the action of mechanical stress, etc. In addition, moisture, aging, thermal decomposition, metal ion migration of electrode materials, existence or change of residual stress, surface pollution, self-healing effect of metallized electrode of materials, volatilization and thickening of working electrolyte, electrolytic corrosion or chemical corrosion of electrode and the influence of impurities or harmful ions are many reasons for the degradation of capacitive electrical parameters.

Inductive components

Inductive components involve transformers, inductors, filter coils, oscillation coils, etc. Most of the faults of inductive components are caused by external factors, such as the temperature rise of transformer and the excessive current passing through the coil due to load short circuit, which will lead to short circuit, short circuit and breakdown of the coil. 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 weldability and so on. Failure is mainly divided into complete damage and poor thermal stability. Thermal stability failure mainly occurs at high or low temperature, which exceeds the working temperature range of the device.

Integrated module and circuit faults

Manifold block faults are mainly caused by open electrode, short electrode, broken lead, mechanical wear, packaging cracks and poor weldability. However, due to its complex internal structure and diverse functions, any part of the integrated circuit can not work normally. The failure types include: complete damage and poor thermal stability.

How to effectively find the failed electronic components and replace or repair the problem? When the circuit fails to work or works abnormally during debugging. First, through the dynamic observation method, that is, when the line equipment is powered on, listen, see, touch, smell and other methods to judge the faults of electronic components. For example: listen to whether the equipment has abnormal sound, and carefully check whether there are smoke, sparks and other conditions in the circuit; Touch whether the components and circuits are hot; Smell if there's a burnt smell. It can also be judged by measuring the on-off condition in the circuit with a multimeter and by measuring various values in normal and abnormal circuits.

The above is the related content of "electronic component failure detection" brought by the core creation test. I hope it can be helpful to you. We will bring more wonderful content in the later stage. The company's testing services cover: electronic component testing and verification, IC authenticity identification, product design and material selection, failure analysis, function testing, factory incoming material inspection, tape braiding and other testing items. Welcome to call Chuangxin testing, we will serve you wholeheartedly.