**9.1 Conduction welding**

During the conduction mode of LBW, heat is transferred to the metal through thermal conductivity. In this mode, low energy is transferred per unit area (0.5 MW/cm<sup>2</sup> ), which is often used for shallow joints to create a wide and shallow weld (**Figure 8**). Due to the low penetration depth in this mode, the gas absorption in the weld pool is low. It is also completely soundless. Typically, this mode can be utilized for applications, which require a high-quality weld e.g. battery sealing applications. The conduction mode is carried out in four steps [3, 5–7, 13, 17], (I) heating of the workpiece surface by the laser radiation, (II) formation of the molten pool, (III) no melt evaporation during the process, and (IV) determination of weld pool shape by the thermal conductivity (**Figure 12**).
