Materials used include:

Metals:
Gold, Kovar, Nickel Iron alloys, OFHC Copper, Copper/Tungsten, Copper/Molybdenum, Molybdenum.

Ceramics:
Alumina (White or Black), Aluminium Nitride, Sapphire.

Metallisations:
Au, Pt/Au, Pt/Ag, Mo, W.

Other:
Silicon, Ferrites, Zirconia, Glass, Quartz.

Solders and Braze Materials:
Sn/Pb, Sn/Pb/Ag, Sn/Ag, Au/Sn, Au/Ge, Ag/Cu, Au/Ni, Cu.