What factor limits the maximum forward current in a junction diode?

The maximum forward current in a junction diode is typically limited by the junction temperature. When current flows through a diode, it generates heat due to the resistance and power dissipation within the device. As the junction temperature rises, the diode’s efficiency can decrease, which can lead to thermal runaway if the current continues to increase.

The relationship between temperature and current is significant because an increase in temperature can reduce the breakdown voltage of the diode and increase leakage current. To prevent damage or failure, manufacturers specify a maximum junction temperature rating, and exceeding this rating while increasing the forward current can result in permanent damage to the device.

In contrast, factors like voltage rating pertain to the maximum voltage the diode can handle without breakdown, while capacitance might influence switching speed or efficiency in AC applications but does not directly limit forward current. Insulation type is more relevant to the electrical isolation of components rather than the operational characteristics of the diode under forward bias.