What happens if a diode breaks?

1, Direct manifestation of diode damage
After a diode is damaged, the most direct manifestation is a change in its electrical performance, which usually leads to the following phenomena:
Open circuit fault: When a diode breaks or opens internally, it will be unable to conduct electricity. This means that in the circuit, the current that should have passed through the diode is blocked, causing the circuit to malfunction. In a rectifier circuit, if the rectifier diode is open circuited, it will not be able to convert AC power to DC power, resulting in the power supply not functioning properly.
Short circuit fault: In contrast to an open circuit, when a short circuit occurs inside a diode, it will lose its unidirectional conductivity and become bidirectional. This can lead to an abnormal increase in current, which may burn out surrounding components or circuit boards. In a voltage regulator circuit, if the voltage regulator diode is short circuited, it will not be able to provide a stable output voltage, which may cause damage to other components in the circuit.
Performance degradation: After long-term operation, diodes may gradually degrade due to aging, thermal stress, and other factors. This is manifested as an increase in the conduction voltage and leakage current of the diode. Although these changes may not be as significant as open or short circuits, they can still affect the stability and performance of the circuit.
2, The impact of diode damage on electronic systems
After a diode is damaged, it not only affects its own function, but may also have a profound impact on the entire electronic system:
Circuit malfunction: As mentioned earlier, diodes usually play a critical role in circuits, such as rectification, voltage regulation, amplification, etc. Once the diode is damaged, these functions cannot be achieved, resulting in the entire circuit not functioning properly. For example, in the power circuit, if the rectifier diode is damaged, the power supply will not be able to output stable DC power, which will affect the power supply of the entire device.
Equipment damage: If the diode is damaged and not detected and replaced in a timely manner, it may cause even greater malfunctions. For example, a short circuit fault may cause an abnormal increase in current and burn out other components on the circuit board; An open circuit fault may cause an abnormal increase in voltage in the circuit, damaging the components connected to it. These chain reactions may ultimately lead to damage to the entire device.
Safety hazard: In some cases, diode damage may also pose a safety hazard. For example, in high-voltage circuits, if a diode is damaged and causes an abnormal increase in voltage in the circuit, it may lead to dangerous events such as electric shock and fire. Therefore, special attention should be paid to the safety and reliability of diodes in high-voltage circuits.
Performance degradation: Even if diode damage does not directly cause circuit failure or equipment damage, it may still lead to a decline in the overall system performance. For example, in an amplification circuit, if the performance of the amplification diode deteriorates, it will lead to problems such as reduced amplification factor and increased distortion. Although these issues may not immediately cause the device to malfunction, they can seriously affect the performance and user experience of the device.
3, Prevention and response measures
To avoid the adverse consequences of diode damage, we can take the following preventive and response measures:
Reasonable selection: When selecting diodes, reasonable selection should be made based on the specific requirements of the circuit, such as operating voltage, current, frequency, etc. Ensure that the selected diode meets the operational requirements of the circuit and has a certain margin.
Heat dissipation design: The diode generates a certain amount of heat during operation. If the heat dissipation is poor, it will accelerate its aging process. Therefore, when designing circuits, heat dissipation issues should be fully considered and effective heat dissipation measures (such as heat sinks, fans, etc.) should be taken.
Regular testing and maintenance: For electronic devices that operate for a long time, regular testing and maintenance should be carried out. By detecting the electrical performance of diodes (such as conduction voltage, leakage current, etc.), damaged components can be promptly detected and replaced.
Protection measures: Install overcurrent, overvoltage and other protection circuits in the circuit to prevent diode damage due to overload, overvoltage and other reasons. These protective measures can effectively improve the reliability and safety of the circuit.
https://www.trrsemicon.com/diode/smd-diode/tvs-diodes-smbj30ca.html