Ceramic matrices for electronic devices and process for forming same

A process for forming unitary ceramic bodies suitable for use in making capacitors which comprises:

• providing a plurality of thin sheets of finely divided ceramic composition bonded with a thermally-fugitive bond, said ceramic composition forming a dense, dielectric layer when fired to sintering temperatures;
• providing on a plurality of spaced areas on each of a plurality of said sheets a coating which consists of thermally-fugitive material and a plurality of granules selected from the class consisting of ceramic and metallic granules of such size as to extend substantially through said coating;
• forming a stack comprising a plurality of said coated sheets with at least certain of the coated areas on said coated sheets being partially superposed;
• consolidating said stack;
• firing said consolidated stack under suitable conditions at temperatures sufficiently high to remove said thermally-fugitive materials and to sinter said ceramic composition into a monolithic block;
• and severing said block into smaller bodies each of which comprises a plurality of thin strata of dense dielectric material, substantial portions of the adjacent surfaces of a plurality of said strata being separated to provide spaces therebetween which extend to edge regions of said body, said separated strata being joined only at edge portions thereof and by a plurality of distinct pillars formed of material selected from the class of ceramic and metallic materials extending from the tops to the bottoms of said spaces, substantially all of said pillars being separate.

A process for forming unitary ceramic bodies suitable for use in making capacitors which comprises:

• providing a plurality of thin sheets of a finely divided ceramic composition bonded with a thermally-fugitive bond, said ceramic composition forming a dense, dielectric layer when fired to sintering temperatures;
• providing on a plurality of spaced areas on each of a plurality of said sheets a coating which consists of thermally-fugitive material and a plurality of granules selected from the class consisting of ceramic and metallic granules of such size as to extend substantially through said coating;
• forming a stack of a plurality of said coated sheets with at least certain of the coated areas on a plurality of said sheets being partially superposed;
• consolidating said stack into a green block;
• severing said green block by vertical cuts therethrough whereby to obtain a plurality of small bodies or chips in each of which at least one of said coated areas is exposed at one of a plurality of edge regions;
• firing said chips under suitable conditions at temperatures sufficiently high to remove said thermally-fugitive materials and to sinter said ceramic composition, whereby to form integral, monolithic, sintered ceramic chips, each of which comprises a plurality of thin strata of dense, dielectric material, substantial portions of the adjacent surfaces of a plurality of said strata in each chip being separated to provide spaces therebetween which extend to edge regions of said chip, said separated strata being joined only at edge portions thereof and by a plurality of distinct pillars formed of material selected from the class of ceramic and metallic materials substantially all of which are separate.

A process for forming a unitary ceramic body suitable for use in making a capacitor which comprises:

• providing a plurality of thin leaves of finely divided ceramic composition bonded with a thermally-fugitive bond, said ceramic composition forming a dense, dielectric layer when fired to sintering temperatures;
• forming a consolidated stack consisting of a plurality of said leaves having interposed between at least two of said leaves a thin layer which consists of thermally-fugitive material and a minor amount of granules selected from the class consisting of ceramic and metallic granules of such size as to extend substantially through said layer, said layer having a smaller area than that of the adjacent leaves and said leaves being so arranged and placed that major portions of the edges of the leaves adjacent said layer are in contact with each other, with said layer extending to an edge region of said consolidated stack;
• and firing said consolidated stack under suitable conditions at temperatures sufficiently high to remove said thermally-fugitive materials and to sinter said ceramic composition, whereby to form an integral, monolithic, sintered ceramic body having a plurality of thin strata of dense dielectric material, substantial portions of the adjacent surfaces of at least two of said strata being separated to provide therebetween a thin space, bounded above and below by said surfaces, and being joined only at edge portions thereof and by at least one distinct pillar formed of material selected from the class of ceramic and metallic materials extending from the top to the bottom of said space, substantially all of said pillars being separate when there are a plurality thereof.