Apparatus for forming cavities without using an insert

An apparatus for forming cavities in at least one ceramic layer having at least one cavity comprising, a first plate to accommodate said at least one ceramic layer having at least one cavity, at least one cavity forming membrane having at least one opening over at least a portion of said at least one cavity in said at least one ceramic layer, such that at least a portion of said at least one opening is over at least a portion of said at least one cavity, a second plate having at least one opening over at least a portion of said at least one membrane, such that at least a portion of said at least one opening is over at least a portion of said opening in said membrane, at least one external pressure application means over said second plate, and at least one internal pressure means over said at least one membrane for providing an internal pressure, wherein said at least one external pressure application means applies external pressure over said second plate and wherein said at least one internal pressure means provides said internal pressure within said at least one cavity through said at least one opening in said membrane to counter said external pressure and prevents said at least one cavity from deforming and thereby forms said at least one ceramic layer having at least one cavity.