The present invention relates to a polymerizable mixture which can be used to form a dielectric material for the preparation of passivation layers in electronic devices. The polymerizable mixture comprises a first monomer and a second monomer which may react to form a copolymer providing excellent film forming capability, excellent thermal properties and excellent mechanical properties. There is further provided a method for forming said copolymers and an electronic device containing said copolymers as dielectric material. Beyond that, the present invention relates to a manufacturing method for preparing a packaged microelectronic structure and to a microelectronic device comprising said packaged microelectronic structure formed by said manufacturing method.