Abstract: The present invention relates to a method for producing a metal-ceramic substrate. The method has the following steps: providing a stack containing a ceramic body, a metal foil, and a solder material in contact with the ceramic body and the metal foil, wherein the solder material has: a metal having a melting point of at least 700° C., a metal having a melting point of less than 700° C., and an active metal; and heating the stack, wherein at least one of the following conditions is satisfied: the high temperature heating duration is no more than 60 min; the peak temperature heating duration is no more than 30 min; the heating duration is no more than 60 min.

Abstract: The invention relates to a method for producing a metal-ceramic substrate and to a furnace suitable for carrying out the method. With the method, a metal-ceramic substrate with increased thermal and current conductivity can be obtained. The method comprises the steps of providing a stack containing a ceramic body, a metal foil, and a solder material in contact with the ceramic body and the metal foil, the solder material comprising a metal having a melting point of at least 700° C., a metal having a melting point of less than 700° C., and an active metal, and heating the stack, the stack passing through a heating zone for heating.

Abstract: A filter comprising first and second BAW resonators. The first BAW resonator having a piezoelectric layer, located between a top electrode and a bottom electrode, and a dielectric layer located between the bottom electrode and an additional electrode. Wherein the dielectric layer, the bottom electrode and the additional electrode are configured to provide an additional capacitance in the resonator. The second BAW resonator having at least one less electrode than the first BAW resonator.

Abstract: A BAW resonator (1) comprises a piezoelectric layer (2) located between a top electrode (4) and a bottom electrode (3) and comprises a dielectric layer (9) located between the bottom electrode (3) and an additional electrode (11), wherein the dielectric layer (9), the bottom electrode (3) and the additional electrode (11) are configured to provide an additional capacitance in the resonator (1). The BAW resonator (1) may be part of a ladder-type resonator arrangement (100).