Method of manufacturing ceramic multi-layer substrate, and unbaked composite laminated body

A method of producing ceramic multilayer substrates comprising:

• (1) forming a green composite laminate comprising a green multilayer mother substrate having first and second opposing main surfaces and comprising a plurality of ceramic green layers containing ceramic powder, and first and second shrink-suppressing layers on the first and second main surfaces of the mother substrate, respectively, wherein the first and second shrink-suppressing layers comprise a powder substantially incapable of being sintered under the sintering conditions for the ceramic powder of the green multilayer mother substrate, by pressing an assembly of the green mother substrate and first and second shrink-suppressing layers;
• (2) pressing the whole of the green composite laminate in the lamination direction of the ceramic green layers;
• (3) forming in the pressed laminate a plurality of first grooves extending from the first shrink-suppressing layer side so as to pass through the first shrink-suppressing layer and reach a part of the green multilayer mother substrate;
• (3) firing the green composite laminate under the sintering conditions for the ceramic powder;
• (4) removing the first and second shrink-suppressing layers to recover a sintered multilayer mother substrate, and
• (5) dividing the multilayer mother substrate along the first grooves to realize a plurality of ceramic multilayer substrates;
• wherein the formed composite laminate is pressed at a pressure higher than that employed in forming the composite laminate.

A method of producing ceramic multilayer substrates comprising:

• (1) forming a green composite laminate comprising a green multilayer mother substrate having first and second opposing main surfaces and comprising a plurality of ceramic green layers containing ceramic powder, and first and second shrink-suppressing layers on the first and second main surfaces of the mother substrate, respectively, wherein the first and second shrink-suppressing layers comprise a powder substantially incapable of being sintered under the sintering conditions for the ceramic powder of the green multilayer mother substrate, by pressing an assembly of the green mother substrate and first and second shrink-suppressing layers;
• (2) pressing the whole of the green composite laminate in the lamination direction of the ceramic green layers;
• (3) forming in the pressed green laminate a plurality of first grooves extending from the first shrink-suppressing layer side so as to pass through the first shrink-suppressing layer and reach a part of the green multilayer mother substrate;
• (4) providing an auxiliary sheet on the first shrink-suppressing layer after the first grooves are formed and pressing the green composite laminate in the lamination direction of the ceramic green layers after the auxiliary sheet is provided is at a higher pressure than that employed in forming the green composite, followed by removing the auxiliary sheet;
• (5) firing the green composite laminate under the sintering conditions for the ceramic powder;
• (6) removing the first and second shrink-suppressing layers to recover a sintered multilayer mother substrate, and
• (7) dividing the multilayer mother substrate along the first grooves to realize a plurality of ceramic multilayer substrates.