# US 5,706,171 A · Flat plate cooling using a thermal paste retainer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,706,171 A - Document ID: US5706171A - Status: Granted - Kind: A - Application number: 08/560,568 - Filed: 1995-11-20 - Granted: 1998-01-06 - Earliest claimed: 1995-11-20 - Assignees: International Business Machines Corporation - Inventors: David Linn Edwards; Sushumna Iruvanti; Gaetano Paolo Messina; Raed A. Sherif - Web page: https://patentgrep.com/patent/US5706171A ## CPC - H05K 7/20454: {with a conformable or flexible structure compensating for irregularities, e.g. cushion bags, thermal paste} - H10W 40/70: Fillings or auxiliary members in containers or in encapsulations for thermal protection or control - H10W 72/07251: {characterised by changes in properties of the bump connectors during connecting} - H10W 72/20: Bump connectors, e.g. solder bumps or copper pillars; Dummy bumps; Thermal bumps - H10W 72/877: {Bump connectors and die-attach connectors} - H10W 90/724: {between a chip and a stacked insulating package substrate, interposer or RDL} - H10W 90/736: {between a chip and a stacked lead frame, conducting package substrate or heat sink} - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract Thermal material such as a paste or gel is confined within a paste gap between a surface of a flat cooling plate and an opposing surface of a chip mounted on a surface of a chip carrier or substrate by forming a partition, preferably in the form of a grid, at the periphery of one or more chips. The partition is located laterally in sufficient proximity to the chip and in communication with the paste gap to form a capillary and thus confine motion of a viscous thermal material to repetitive bidirectional flow out of and into the paste gap with relative motion of the chip and the surface of the flat cooling plate. The grid is preferably fitted closely within grooves formed in the surface of the flat cooling plate and preferably supported by leaf springs so that thermal material is confined within cells of the grid while providing support and/or damping of relative motion between the flat cooling plate and the substrate or carrier. ## Claims ### Claim 1 An electronic package including: at least one chip mounted on a surface of a carrier, a cooling means having a surface opposing a surface of said at least one chip and said carrier, a space between said at least one chip and said surface of said cooling means defining a paste gap containing a viscous thermal material, and a partition surrounding at least a major portion of said at least one chip and spaced therefrom and forming a capillary at a periphery of said at least one chip, said capillary containing said viscous thermal material. ### Claim 2 (depends on 1) An electronic package as recited in claim 1, wherein at least a portion of said partition receives an electronic component other than an integrated circuit chip. ### Claim 3 (depends on 1) An electronic package as in claim 1, wherein said partition is connected to said cooling means and said carrier, said partition defining a cell retaining said thermal material and said chip. ### Claim 4 (depends on 1) An electronic package as in claim 1, wherein said partition is connected to said cooling means via elastic means. ### Claim 5 (depends on 1) An electronic package as in claim 1, wherein said electronic package is a chip/substrate/cover structure. ### Claim 6 An electronic package including: at least one chip mounted on a surface of a carrier, a cooling means having a surface opposing a surface of said at least one chip and said carrier, a space between said at least one chip and said surface of said cooling means defining a paste gap containing a viscous thermal material, and a partition surrounding at least a major portion of said at least one chip and spaced therefrom and forming a capillary at a periphery of said at least one chip said, capillary containing said thermal material, wherein said partition is fired within a groove in said surface of said cooling means. ### Claim 7 (depends on 6) An electronic package as recited in claim 6, wherein said partition is in the form of a grid received within said groove. ### Claim 8 (depends on 7) An electronic package as recited in claim 7, further including a leaf spring interposed between a bottom of said groove and said grid. ### Claim 9 An electronic package including: at least one chip mounted on a surface of a carrier, a cooling means having a surface opposing a surface of said at least one chip and said carrier, a space between said at least one chip and said surface of said cooling means defining a paste gap containing a viscous thermal material, and a partition surrounding at least a major portion of said at least one chip and spaced therefrom and forming a capillary at a periphery of said at least one chip, said capillary containing said thermal material, wherein said partition contacts a surface of said carrier. ### Claim 10 (depends on 8) An electronic package as recited in claim 8, wherein said grid contacts a surface of said carrier. ### Claim 11 A structure for mounting art electronic component comprising: a carrier connected to said component; a thermal material contacting said component; cooling means contacting said thermal material; and a grid connected to said carrier and said cooling means, said grid including cells having a dimension larger than that of said component, one of said cells receiving said component, such that said grid causes said thermal material to be retained substantially between said component and said cooling means. ### Claim 12 (depends on 11) A structure as in claim 11, wherein said grid contacts said cooling means via elastic means, so as to permit relative movement between said carrier and said cooling means. ### Claim 13 (depends on 12) A structure as in claim 12, wherein said grid contacts said cooling means by a connection comprising an elastic leaf spring. ### Claim 14 (depends on 11) A structure as in claim 11, wherein said cooling means includes grooves receiving said grid. ### Claim 15 (depends on 11) A structure as in claim 11, wherein said grid is integral with said carrier. ### Claim 16 A structure for mounting an electronic component comprising: a carrier connected to said component: a thermal material contacting said component: cooling means contacting said thermal material: and a grid connected to said carrier and said cooling means, said grid including cells having a dimension larger than that of said component, one of said cells receiving said component, such that said grid causes said thermal material to be retained substantially between said component and said cooling means, wherein said grid includes partitions which substantially surround said component, said partitions being spaced from said component such that said partitions cause capillary action of said thermal material around said component. ### Claim 17 (depends on 4) An electronic package as in claim 4, wherein said elastic means comprises springs. ### Claim 18 (depends on 11) A structure as in claim 11, wherein said structure for mounting an electronic component is a chip/substrate/cover structure.