Summary of common capacitor failure principles (I)

The main failure modes of electronic components include, but are not limited to, open circuit, short circuit, burn, explosion, leakage, functional failure, drift of electrical parameters, and non-stable failure. For hardware engineers, the failure of electronic components is a very troublesome task. For example, a certain semiconductor device has a good appearance but is in fact half-failed or fully failed. It takes a lot of time to debug the hardware circuit, and sometimes it even crashes. Today we mainly talk about capacitors, resistors and inductors.

Capacitor failure mode and mechanism:

Common failure modes of capacitors include: breakdown short circuit; fatal failure open circuit; fatal failure change of electrical parameters (including capacitance overshoot, loss tangent increase, insulation performance decrease or leakage current increase); some functional failure leakage; Some of the functional failure lead corrosion or fracture; fatal failure insulator breakdown; fatal failure insulator surface arcing; part of the function failure, causing the capacitor to fail due to a variety of reasons. Different types of capacitors have different materials, structures, manufacturing processes, properties and operating environments, and their failure mechanisms are also different.

The main failure mechanism that causes capacitor breakdown:

1 Dielectric material has defects or defects, or contains conductive impurities or conductive particles;

2 Electrical aging and thermal aging of the dielectric;

3 Electrochemical reaction inside the dielectric;

4 silver ion migration;

5 Dielectrics are mechanically damaged during capacitor manufacturing;

6 Dielectric molecular structure changes;

7 Arc flash between high and low humidity environments;

8 The dielectric short circuit under mechanical stress.

Prevention of capacitor overvoltage failure:

Capacitors are easily broken down in overvoltage conditions, and instantaneous high voltages in real applications are common.