AMB stands for Active Metal Brazing, i.e. an active solder. This solder reacts with the ceramic thanks to activators (e.g. titanium) and forms a reaction layer, which is wetted by the solder material and forms a solder joint with the metal. Silicon nitride is usually used as the insulating ceramic.

Due to its good flexural fatigue strength and the good thermal conductivity of Si3N4, these substrates are mostly used in automotive power electronics.