Thermocompression welding - also called “thermo-compression bonding” - is used to produce joints by the principle of “indirect heating”. The two parts are joined under the simultaneous influence of force and heat. The type of bond corresponds to diffusion welding, i.e. the bond is not produced by melting at the contact points, but by metallic solid body diffusion.
One of the most common materials used is gold. Gold is especially preferred due to its excellent resistance to oxidation. Other materials can be bonded as well, but oxidation has to be removed before bonding.