PCBA Tech - Failure Analysis of Electronic Components in PCBA

In PCBA, electronic components are the basic components of electronic products. The failure of components will limit the normal operation of equipment. In the actual work of electronic components, due to the influence of various factors, electronic components will fail, so it is necessary to do a good job in the failure detection of electronic components, identify the causes of failure, find appropriate methods to deal with the problem, shorten the time for troubleshooting, and improve the quality of electronic components. This paper mainly analyzes the reasons for the failure of electronic components and the methods to solve the problem. 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.

PCBA 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.

Electrical Over Stress (EOS. Printed circuit boards and its components (PCB&PCBA) are the core components of electronic products. The reliability of PCB&PCBA directly determines the reliability of electronic products. In order to ensure and improve the quality and reliability of electronic products, a comprehensive physical and chemical analysis of the failure is conducted to confirm the internal mechanism of the failure, so as to propose targeted improvement measures.