A method for manufacturing a composite panel is described. The method includes producing a first wall, a second wall, a third wall and a fourth wall from composite materials including an oxide matrix and long oxide fibres; from the first and second walls, producing a cellular core including a plurality of cells, each cell including a first end and an opposing second end, covering the first and second ends of the cells of the cellular core with the third wall and the fourth wall, respectively, so as to close the ends of said cells.

A method for the joining of ceramic pieces with a hermetically sealed joint comprising brazing a continuous layer of joining material between the two pieces. The wetting and flow of the joining material is controlled by the selection of the joining material, the joining temperature, the time at temperature, the joining atmosphere, and other factors. The ceramic pieces may be aluminum nitride and the pieces may be brazed with an aluminum alloy under controlled atmosphere. The joint material is adapted to later withstand both the environments within a process chamber during substrate processing, and the oxygenated atmosphere which may be seen within the shaft of a heater or electrostatic chuck.

A method for the joining of ceramic pieces with a hermetically sealed joint comprising brazing a continuous layer of joining material between the two pieces. The wetting and flow of the joining material is controlled by the selection of the joining material, the joining temperature, the time at temperature, the joining atmosphere, and other factors. The ceramic pieces may be aluminum nitride and the pieces may be brazed with an aluminum alloy under controlled atmosphere. The joint material is adapted to later withstand both the environments within a process chamber during substrate processing, and the oxygenated atmosphere which may be seen within the shaft of a heater or electrostatic chuck.

An electrostatic chuck includes a ceramic top plate layer made of a beryllium oxide material, a ceramic bottom plate layer made of a beryllium oxide material, a ceramic middle plate layer disposed between the ceramic top plate layer and the ceramic bottom plate layer, an electrode layer disposed between the ceramic top plate layer and the ceramic middle plate layer, and a heater layer disposed between the ceramic middle plate layer and the ceramic bottom plate layer. The electrode layer joins and hermetically seals the ceramic top plate layer to the ceramic middle plate layer, and the heater layer joins and hermetically seals the ceramic middle plate layer to the ceramic bottom plate layer.

A method is described for introducing cooling cavities into CMC components beneath flanges such as T-shaped flanges within the CMC components. During layup, preform is made having flanges formed from a Y-shaped weave in which plies of woven ceramic fiber tows form a radial flange section extending from a base of the preform and two bifurcated arms. The plies of the two bifurcated arms and plies of the base form a cooling cavity having a triangular cross section beneath the flange. Cooling fluid inlet passages are provided to permit cooling fluid to enter the cooling cavity and thereby cool the internal region of the CMC component to reduce formation of thermal stresses.