# US 5,707,476 A · Method for forming multiple cavity products > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,707,476 A - Document ID: US5707476A - Status: Granted - Kind: A - Application number: 08/530,499 - Filed: 1995-09-19 - Granted: 1998-01-13 - Earliest claimed: 1995-09-19 - Assignees: International Business Machines Corporation - Inventors: Raschid Jose Bezama; John Ulrich Knickerbocker; Govindarajan Natarajan; Joseph Gang Zhou - Web page: https://patentgrep.com/patent/US5707476A ## CPC - B32B 37/26: with at least one layer which influences the bonding during the lamination process, e.g. release layers or pressure equalising layers - B32B 37/0023: {around holes, apertures or channels present in at least one layer} - H10W 70/05: of insulating or insulated package substrates, or of interposers, or of redistribution layers (manufacture or treatment of leadframes H10W70/04) - H10W 70/095: {of vias therein} - B32B 2315/02: Ceramics - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract The present invention relates generally to a new apparatus and method for simultaneously laminating a plurality of substrates having at least one cavity. More particularly, the invention encompasses apparatus and method for fabricating cavities in MLC (multi-layer ceramic). A membrane with or without an opening is placed on the top surface of the unlaminated green sheet having at least one cavity and then standard pressure is applied to laminate the green sheets, while simultaneously a counter pressure is applied in the cavity to prevent the cavity from deforming or collapsing. This is done to simultaneously form a plurality of cavity substrates. ## Claims ### Claim 1 A method of laminating a plurality of ceramic substrates having at least one cavity, comprising the steps of: (a) placing at least one ceramic layer having at least one cavity over a first plate, (b) placing at least one cavity forming membrane over at least a portion of said at least one cavity, (c) placing a first porous plate adjacent at least a portion of said at least one cavity forming membrane, wherein said first porous plate has pores for fluid passage, (d) putting pressure on at least a portion of said first porous plate so that said first plate and said first porous plate comes closer, and simultaneously pressurizing through said at least one cavity forming membrane said at least one cavity in said ceramic layer with at least one fluid to counter the pressure from said first porous plate, thereby laminating said substrate with at least one cavity. ### Claim 2 (depends on 1) The method of claim 1, wherein a plurality of ceramic layers are placed between said first plate and said first porous plate. ### Claim 3 (depends on 1) The method of claim 1, wherein the material for said at least one ceramic layer is selected from a group consisting of alumina, alumina with glass frits, aluminum nitride, borosilicate and glass ceramic. ### Claim 4 (depends on 1) The method of claim 1, wherein pressure differential between said first plate and said first porous plate is under about 700 psi, and more preferably between about 100 psi and about 200 psi. ### Claim 5 (depends on 1) The method of claim 1, wherein at least one non-sticky material is placed between said first plate and said at least one ceramic layer. ### Claim 6 (depends on 5) The method of claim 5, wherein said at least one non-sticky material is selected from a group consisting of polymer, elastomer, polyethylene terephthalate, latex rubber, and polyethylene. ### Claim 7 (depends on 1) The method of claim 1, wherein said first plate, said at least one ceramic layer and said first porous plate are inside a frame. ### Claim 8 (depends on 1) The method of claim 1, wherein said at least one membrane follows the contours of said at least one cavity in said at least one ceramic layer. ### Claim 9 (depends on 1) The method of claim 1, wherein said pressure on said first porous plate is a hydraulic pressure and wherein said pressure in said at least one cavity is from a fluid. ### Claim 10 (depends on 9) The method of claim 9, wherein said fluid is a gas selected from a group consisting of air, helium, nitrogen, oxygen and inert gas. ### Claim 11 (depends on 1) The method of claim 1, wherein said ceramic substrate is pre-heated prior to the application of said pressure. ### Claim 12 (depends on 1) The method of claim 1, wherein said at least one cavity forming membrane is pre-formed to the shape of said at least one cavity. ### Claim 13 (depends on 1) The method of claim 1, wherein said first porous plate has a porosity of between about 8 percent to about 50 percent, and preferably about 15 percent. ### Claim 14 A method of laminating a plurality of ceramic substrates having at least one cavity, comprising the steps of: (a) placing at least one ceramic layer having at least one cavity over a first plate, (b) placing at least one cavity forming membrane having at least one opening over at least a portion of said at least one cavity, such that at least a portion of said opening in said membrane is over at least a portion of said cavity, (c) placing a first porous plate adjacent at least a portion of said at least one opening in said membrane, wherein said first porous plate has pores for fluid passage, (d) putting pressure on at least a portion of said first porous plate so that said first plate and said first porous plate come closer, and simultaneously pressurizing through said at least one cavity forming membrane said at least one cavity in said ceramic layer with at least one fluid to counter the pressure from said first porous plate, thereby laminating said plurality of substrates with at least one cavity. ### Claim 15 (depends on 14) The method of claim 14, wherein a plurality of ceramic layers are placed between said first plate and said first porous plate. ### Claim 16 (depends on 14) The method of claim 14, wherein the material for said at least one ceramic layer is selected from a group consisting of alumina, alumina with glass frits, aluminum nitride, borosilicate and glass ceramic. ### Claim 17 (depends on 14) The method of claim 14, wherein pressure differential between said first plate and said first porous plate is under about 700 psi, and more preferably between about 100 psi and about 200 psi. ### Claim 18 (depends on 14) The method of claim 14, wherein at least one non-sticky material is placed between said first plate and said at least one ceramic layer. ### Claim 19 (depends on 18) The method of claim 18, wherein said at least one non-sticky material is selected from a group consisting of polymer, elastomer, polyethylene terephthalate, latex rubber, and polyethylene. ### Claim 20 (depends on 14) The method of claim 14, wherein said first plate, said at least one ceramic layer and said first porous plate are inside a frame. ### Claim 21 (depends on 14) The method of claim 14, wherein said pressure on said first porous plate is a hydraulic pressure and wherein said pressure in said at least one cavity is from a fluid. ### Claim 22 (depends on 21) The method of claim 21, wherein said fluid is a gas selected from a group consisting of air, helium, nitrogen, oxygen and inert gas. ### Claim 23 (depends on 14) The method of claim 14, wherein said ceramic substrate is pre-heated prior to the application of said pressure. ### Claim 24 (depends on 14) The method of claim 14, wherein said first porous plate has a porosity of between about 8 percent to about 50 percent, and preferably about 15 percent.