# US 5,346,749 A · Process for obtaining insulating ceramic inserts by multilayer stacking > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,346,749 A - Document ID: US5346749A - Status: Granted - Kind: A - Application number: 08/038,599 - Filed: 1993-03-23 - Granted: 1994-09-13 - Earliest claimed: 1992-03-23 - Assignees: N-Xeram - Inventors: Armand Bettinelli - Web page: https://patentgrep.com/patent/US5346749A ## CPC - H01B 17/58: Tubes, sleeves, beads, or bobbins through which the conductor passes - B28B 1/002: {assembled from preformed elements} - H01B 19/00: Apparatus or processes specially adapted for manufacturing insulators or insulating bodies {(manufacture of porcelain for electric insulation C04B33/26)} - Y10S 428/901: Printed circuit - Y10T 428/24917: including metal layer - Y10T 428/24926: including ceramic, glass, porcelain or quartz layer - H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K}) - B28B: SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER (foundry moulding B22C; working stone or stone-like material B28D; shaping of substances in a plastic state, in general B29C; making layered products not composed wholly of these substances B32B) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A process for manufacturing insulating ceramic inserts used as sealed passages for electrical conductors through a metallic wall, is described wherein a green ceramic plate is subjected to silk-screen printing with the aid of a conducting ink, generally in ring-shaped patterns. The patterns are pressed and holes are pierced through the center of the ring and through at least one other green plate. The silk-screen printed plate is pressed against the at least one other green plate, or between two other green plates, bringing the holes into coincidence. A cut-out is made around each of the holes and the outer lateral surface of the part obtained is metallized. The part is then heat treated in order to fire and sinter same. It also is possible for the sintering to be performed before the metallization of the outer lateral surface. ## Claims ### Claim 1 A product produced by a process for manufacturing an insulating ceramic insert, said product comprising a ceramic body defined by two non-metallized end faces, an external lateral surface and at least one bore joining said two end faces, wherein said process comprises: casting at least two plane sheets from a slip of insulating ceramic powder to obtain at least two green sheets, printing ring-shaped patterns, by silk screening, on at least one face of one of said green sheets with the aid of a conducting metallization ink or paste, performing a pressing operation on the silk-screen printed sheet, performing a punching operation on all said sheets to obtain a number of holes, each of said holes of said silk-screen printed sheet matching the interior of a ring of said ring-shaped patterns and having a diameter less than that of holes of the other sheets, stacking said sheets by bringing into coincidence the axes of the various holes, thereby obtaining said at least one bore, performing a pressing operation to agglomerate said sheets, performing a cutting-out operation around said at least one bore to obtain said external lateral surface and thereby fabricating at least one green insert, metallizing said at least one green insert on its external lateral surface, and performing a heat treatment to fire and sinter said insert. ### Claim 2 A product produced by a process for manufacturing an insulating ceramic insert, said product comprising a ceramic body defined by two non-metallized end faces, an external lateral surface of any shape and at least one bore joining said two end faces, wherein said process comprises: casting at least two plane sheets from a lip of insulating ceramic powder to obtain at least two green sheets, printing ring-shaped patterns, by silk-screening, on at least one face of one of said green sheets with the aid of a conducting metallization ink or paste, performing a pressing operation on the silk-screen printed sheet, performing a punching operation on all said sheets to obtain a number of holes, each of said holes of said silk-screen printed sheet matching the interior of a ring of said ring-shaped patterns and having a diameter less than that of holes of the other sheets, stacking said sheets by bringing into coincidence the axes of the various holes, thereby obtaining said at least one bore, performing a pressing operation to agglomerate said sheets, performing a cutting-out operation around said at least one bore to obtain said external lateral surface and thereby fabricating at least one green insert, performing a heat treatment to fire and sinter said insert, metallizing said sintered insert over its external lateral surface, and performing a lapping operation to remove the metallization from the end faces. ### Claim 3 (depends on 1) A product according to claim 1, wherein three green ceramic sheets are cast, the silk-screen printed sheet is thicker than the other two sheets and is silk-screen printed on its two faces, and, upon stacking, said silk-screen printed sheet is inserted between said other two sheets. ### Claim 4 (depends on 1) A product according to claim 1, wherein each of said green ceramic sheets is obtained by stacking several elementary green ceramic sheets. ### Claim 5 (depends on 1) A product according to claim 1, wherein each of the silk-screen printed patterns is a circular ring, the central circle of which corresponds to a bore of said insert. ### Claim 6 (depends on 1) A product according to claim 1, wherein upon stacking of said sheets, the ring-shaped patterns are partially covered. ### Claim 7 (depends on 2) A product according to claim 2, wherein three green ceramic sheets are cast, said silk-screen printed sheet is thicker than the other two sheets and is silk-screen printed on its two faces, and, upon stacking, said silk-screen printed sheet is inserted between said other two sheets. ### Claim 8 (depends on 2) A product according to claim 2, wherein each of said green ceramic sheets is obtained by stacking several elementary green ceramic sheets. ### Claim 9 (depends on 2) A product according to claim 2, wherein each of the silk-screen printed patterns is a circular ring, the central circle of which corresponds to a bore of said insert. ### Claim 10 (depends on 2) A product according to claim 2, wherein, upon stacking of said sheets, the ring-shaped patterns are partially covered. ### Claim 11 An insulating ceramic insert, comprising a sintered ceramic body having two non-metallized end faces, a metallized external lateral surface, means defining at least one bore connecting said two end faces and being electrically insulated from said metallized external surface, said bore including a cylindrical central portion, at least one metallized shoulder positioned within said ceramic body and at least partially surrounding an end of said cylindrical central portion, said bore extending to at least one opening of a diameter greater than that of said cylindrical central portion and said at least one-opening providing access to said shoulder and to said cylindrical central portion. ### Claim 12 (depends on 11) An insulating ceramic insert according to claim 11, comprising at least two ceramic sheets. ### Claim 13 (depends on 12) An insulating ceramic insert according to claim 12, wherein one of said two sheets is provided with a silk-screen printed pattern. ### Claim 14 (depends on 13) An insulating ceramic insert according to claim 13, wherein said silk-screen printed sheet is thicker than the other sheet. ### Claim 15 (depends on 11) An insulating ceramic insert according to claim 11, comprising at least three ceramic sheets. ### Claim 16 (depends on 15) An insulating ceramic insert according to claim 15, wherein one of said sheets is provided with a silk-screen printed pattern on its two faces. ### Claim 17 (depends on 16) An insulating ceramic insert according to claim 16, wherein said silk-screen printed sheet is disposed between the other two sheets. ### Claim 18 (depends on 13) (Amended.) An insulating ceramic insert according to claim 13, wherein said silk-screen printed pattern comprises at least one circular ring having a central circle corresponding to said at least one bore of said insert. ### Claim 19 (depends on 16) An insulating ceramic insert according to claim 16, wherein said silk-screen printed pattern comprises at least one circular ring having a central circle corresponding to said at least one bore of said insert. ### Claim 20 (depends on 18) An insulating ceramic insert according to claim 18, wherein said silk-screen printed pattern is partially covered. ### Claim 21 (depends on 19) An insulating ceramic insert according to claim 19, wherein said silk-screen printed pattern is partially covered. ### Claim 22 (depends on 12) An insulating ceramic insert according to claim 12, wherein at least one of said ceramic sheets comprises several elementary ceramic sheets. ### Claim 23 (depends on 15) An insulating ceramic insert according to claim 15, wherein at least one of said ceramic sheets comprises several elementary ceramic sheets. ### Claim 24 (depends on 1) A product according to claim 1, wherein metallization of said green insert is selectively performed on said external lateral surface thereof. ### Claim 25 (depends on 1) A product according to claim 1, wherein metallization of said green insert is performed on the entire external surface and a lapping operation is subsequently performed to remove metallization from said end faces. ### Claim 26 (depends on 2) A product according to claim 2, wherein metallization of said green insert is selectively performed on said external lateral surface thereof. ### Claim 27 (depends on 2) A product according to claim 2, wherein metallization of said green insert is performed on the entire external surface and a lapping operation is subsequently performed to remove metallization from said end faces. ### Claim 28 (depends on 1) A product according to claim 1, wherein said product contains more than one bore adjoining said two end faces. ### Claim 29 (depends on 2) A product according to claim 2, wherein said product contains more than one bore adjoining said two end faces. ### Claim 30 (depends on 11) An insert according to claim 11, wherein said means defines more than one bore connecting said two end faces. ### Claim 31 (depends on 11) An insert according to claim 11, further comprising a conductor positioned within said bore and brazed to said at least one metallized shoulder.