Principle of passive electronic component failure

 

The principle of passive electronic component failure

The failure of the passive electronic component is affected by factors such as humidity, temperature, voltage, and machinery.

The effect of temperature changes on capacitance

The temperature change will cause the dielectric loss of the capacitor to charge, thereby affecting its service life. When the temperature rises by 10°C, the life of the capacitor is reduced by 50%, and at the same time, it also causes a change in the resistance-capacitance time constant, and even a thermal breakdown occurs due to excessive dielectric loss.

In addition, the increase in temperature will also reduce the insulation performance of inductors, transformers, chokes, etc.

Temperature causes failure

If the temperature is too high， when dust containing acid and alkali falls on the circuit board, it will corrode the solder joints and wiring of the components, causing the solder joints to fall off and the joints to break.

Excessive temperature is also the main cause of leakage coupling.

The excessive voltage causes component failure

The stability of the voltage applied to the components is an important condition to ensure the normal operation of the components. Excessive voltage will increase the heat loss of components and even cause an electrical breakdown. For capacitors, the failure rate is proportional to the 5th power of the capacitor voltage. For integrated circuits, a voltage exceeding the maximum allowable voltage value will cause direct damage to the components.

Voltage breakdown refers to the highest withstand voltage that electronic components can withstand. If the allowable value is exceeded, there is a risk of failure during the period. The manifestations of the failure of active components and passive components are slightly different, but there are also allowable upper limits of voltage. Transistor components have a withstand voltage value. Exceeding the withstand voltage value will damage the components, such as exceeding the withstand voltage value of diodes, capacitors, etc., a voltage exceeding the withstand voltage value of the components will cause them to be broken down, and if the energy is large, it will cause thermal breakdown, The component will be scrapped.

Vibration and impact

Mechanical vibration and shock will accelerate the failure of some internally defective components and cause catastrophic failures. Mechanical vibration will also loosen solder joints and crimping points, resulting in poor contact. If vibration leads to undesirable contact between wires, it will have some unexpected consequences.

The humidity is too low and it is easy to generate static electricity, so the humidity of the environment should be controlled at a reasonable level.