Laser welding is a strongly growing technology that opens up new fields of application. Due to the focussed heat input and the high velocities, the heat-affected zone of the base material is closely limited and undesired material modifications can thus be avoided to a great extent. Even multilayer stacks made of thin sheet metal can be welded with good process reliability and low distortion. Here, the joining of a multilayer stack made of mechanical microstructured sheets with 0.63 and 1mm thickness by laser welding is described. Some unexpected effects that occurred during the process are discussed.