Ultrafast high-temperature sintering method

A method for producing a sintered inorganic substrate, comprising:

• providing an inorganic substrate (1) to be sintered,
• providing the inorganic substrate (1) between a first thermally conductive substrate (2) and a second thermally conductive substrate (3), wherein the first (2) and second (3) thermally conductive substrates comprise carbon,
• providing the first (2) and the second (3) thermally conductive substrate and the inorganic substrate (1) between a third thermally conductive substrate (4) and a fourth thermally conductive substrate (5),
• heating the third (4) and/or the fourth (5) thermally conductive substrate at a heating rate of at least 50°C./s to a temperature between 750° C. and 1400° C., preferably between 900° C. and 1250° C., thereby heating the first (2) and/or the second (3) thermally conductive substrate, respectively, and
• sintering the inorganic substrate (1) by heating the inorganic substrate (1) at a temperature between 750° C. and 1400° C., preferably between 900° C. and 1250° C. with the heated first (2) and/or second (3) thermally conductive substrate,
• wherein the third (4) and the fourth (5) thermally conductive substrates comprise, independently from one another, one or more metal nitride and/or metal oxide.