The rated current of the diode is the main nominal value, such as the 5A/100v diode, the 5A is the rated current. Typically the rated current is defined as the average current rating of the diode. But some of the test is Fang Bo, that is, the average value of 5A of the square wave current. Some have to test the premise is DC, which is able to pass through the 5A DC current. In theory, for a silicon diode, a diode with a square wave as a test condition can pass a greater direct current, because the same average current of a square wave is more than a direct current. Then the 5A diode is certain to pass through the 5A current? Not necessarily, this is related to the temperature, when your heat dissipation condition is not good enough, then the diode can pass through the current will be junction temperature limit.