Is it necessary to replace the positive and negative electrodes of the soldered rectifier diode if it is damaged

Is it necessary to replace the positive and negative electrodes of the soldered rectifier diode if it is damaged

There are two types of diode breakdown:

1. Zener breakdown: Zener diodes operate using this characteristic. With the addition of reverse voltage, under the condition of resistance current limiting, the breakdown voltage at both ends of the diode remains basically unchanged.

2. Avalanche breakdown:

If the load current in the forward working area (AB section) is too high, the reverse voltage in the reverse breakdown area (CD) is too high, or the limiting resistance is too small and the reverse overcurrent occurs, it will cause irreversible breakdown of the diode. This is a destructive breakdown, usually in a short circuit state.

If the breakdown causes a short circuit and generates excessive heat, it can lead to further cracking or combustion, which may be an open circuit state.

To avoid the occurrence of breakdown, it is necessary to select the appropriate type based on the actual working current and leave sufficient margin as much as possible. High power diode also need to meet the heat dissipation needs.