The main problem of joining metal to ceramic by means of soldering is the different thermal expansion coefficients (CTE) of the materials. The greater this difference and the higher the soldering temperature, the greater are the "frozen" voltages in the ceramic-metal composite at room temperature. Therefore, it is attempted to use metal alloys such as Ni42 or Kovar, as they have a CTE similar to aluminum oxide at room temperature. In addition, an attempt is made to adapt the shape and material thickness of the metal parts in such a way that composite stresses are reduced by plastic deformation. Alumina Systems distinguishes between three types of soldering as a connection technique.