High-temperature and wear-resistant ceramics require new joining technologies for manufacturing large-sized and complex components from segments with multi-functional characteristics. Special ceramic foils were developed (LPS-SiC foils-Liquid-Phase-Sintering) for the joining of the non-oxide ceramics-silicon nitride Si3N4. Different concentration of sinter additive in the foils has an influence on the sinter temperature. Pressure- and vacuum-tight joints could be produced through diffusion joining by means of adjusted foils, which show a strength high enough for application at the temperatures up to 1600-1700℃.