# US 5,345,107 A · Cooling apparatus for electronic device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,345,107 A - Document ID: US5345107A - Status: Granted - Kind: A - Application number: 07/839,071 - Filed: 1992-02-20 - Granted: 1994-09-06 - Earliest claimed: 1989-09-25 - Assignees: Hitachi, Ltd. - Inventors: Takahiro Daikoku; Nobuo Kawasaki; Noriyuki Ashiwake; Keizou Kawamura; Shizuo Zushi; Mitsuo Miyamoto; Atsushi Morihara - Web page: https://patentgrep.com/patent/US5345107A ## CPC - F28F 13/00: Arrangements for modifying heat-transfer, e.g. increasing, decreasing (F28F1/00 - F28F11/00 take precedence) - H10W 40/47: by flowing liquids, e.g. forced water cooling - H10W 40/774: {Pistons, e.g. spring-loaded members} - H10W 90/00: Package configurations - F28F 2013/005: {Thermal joints} - H10W 72/07251: {characterised by changes in properties of the bump connectors during connecting} - H10W 72/07353: {changes in shapes} - H10W 72/20: Bump connectors, e.g. solder bumps or copper pillars; Dummy bumps; Thermal bumps - H10W 72/334: {Cross-sectional shape, i.e. in side view} - H10W 72/877: {Bump connectors and die-attach connectors} - H10W 72/879: {Bump connectors and bond wires} - H10W 72/931: {Shapes of bond pads} - F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16) - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract The present invention relates to a cooling apparatus for an electronic device, in which a cooling solid body in close contact through thermal conductive fluid with a heat transfer portion of the electronic device is provided, on its one surface in contact with the electronic device, with a number of grooves communicating with the outside of the heat transfer portion, and a spring member for elastically pressing this cooling solid body on the electronic device is provided for forcing the cooling solid body into close contact with the electronic device by means of the thermal conductive fluid in a third layer. ## Claims ### Claim 1 A cooling apparatus for an electronic device, comprising: an electronic device; a cooling solid body for eliminating heat produced by said electronic device; a highly viscous fluid layer containing thermal conductive powder having a high thermal conductivity sandwiched between a heat transfer surface of said electronic device and a heat transfer surface of said cooling solid body; pressurizing means for forcing said cooling solid body into close contact with said electronic device; and multiple grooves which are formed on one of the heat transfer surface of said electronic device and the heat transfer surface of said cooling solid body and which are communicated with space surrounding one of said electronic device and said cooling solid body having the heat transfer surface, said pressurizing means comprising an elastic member for pressing said cooling solid body on said electronic device and for pressing the highly viscous fluid layer constantly to keep the fluid layer as a thin layer. ### Claim 2 (depends on 1) A cooling apparatus for an electronic device as recited in claim 1, wherein the highly viscous fluid layer comprises a fluid which is hard to wet and spread over the surface of a solid. ### Claim 3 (depends on 2) A cooling apparatus for an electronic device as recited in claim 2, wherein the highly viscous fluid layer comprises grease or a thermal conductive adhesive. ### Claim 4 (depends on 3) A cooling apparatus for an electronic device as recited in claim 3, wherein the highly viscous fluid layer comprises a high viscous grease. ### Claim 5 (depends on 1) A cooling apparatus for an electronic device as recited in claim 1, wherein the capacity of the grooves is larger than the volume of the highly viscous fluid layer sandwiched between said electronic device and said cooling solid body between adjacent ones of the grooves so that space is left in each of the grooves when some of the highly viscous fluid layer between the adjacent ones of the grooves enters the adjacent ones of the grooves. ### Claim 6 A cooling apparatus for an electronic device with a heat transfer surface, comprising a cooling solid body, a spring which forces the cooling solid body into close contact with the heat transfer surface of the electronic device to which surface is applied a highly viscous fluid layer containing thermal conductive powder with high thermal conductivity hardly wetting body, and said spring presses the highly viscous fluid layer constantly to keep the fluid layer as a thin layer, wherein one of a heat transfer surface of the electronic device and the heat transfer surface of the cooling solid body is flat, the other heat transfer surface is a grooved surface including flat heat transfer surface portions and multiple grooves defined between the flat heat transfer surface portions and communicates with an outside of one of said electronic device and said cooling solid body having the grooved heat transfer surface, and the capacity of each of the grooves is larger than the volume of a portion of the highly viscous fluid layer applied to a corresponding flat heat transfer surface portion between adjacent ones of the grooves. ### Claim 7 (depends on 6) A cooling apparatus for an electronic device as recited in claim 6, wherein the section of each of the grooves tapers from the open end of the groove provided at a corresponding heat transfer surface portion of the cooling solid body to the narrow bottom of the groove. ### Claim 8 (depends on 6) A cooling apparatus for an electronic device as recited in claim 6, wherein all the grooves communicate with one another. ### Claim 9 (depends on 8) A cooling apparatus for an electronic device as recited in claim 8, wherein the cooling solid body includes a through-hole extending from the heat transfer surface to the opposite surface of the cooling solid body, each of the grooves communicates with the through-hole so as to open to the outside of the cooling solid body and communicates with space surrounding said cooling solid body. ### Claim 10 (depends on 6) A cooling apparatus for an electronic device as recited in claim 6, the electronic device comprises a multichip module with a high thermal conductive ceramic package. ### Claim 11 A cooling apparatus for an electronic device, comprising a cooling solid body in close contact through a highly viscous fluid layer containing thermal conductive powder and having a high thermal conductivity with a heat transfer surface of the electronic device, and multiple grooves which are formed on one of the heat transfer surface of said electronic device and the heat transfer surface of said cooling solid body and which are communicated with the outside of the heat transfer surface, the capacity of said grooves is greater than the volume of the highly viscous fluid layer sandwiched between said heat transfer surfaces, and each of the grooves leaves therein space communicating with an outside of the heat transfer surface when the highly viscous fluid layer is received within said grooves, and an elastic member is provided for pressing to force said cooling solid body into close contact with the electronic device and for pressing the highly viscous fluid layer constantly to keep the fluid layer as a thin layer. ### Claim 12 (depends on 11) A cooling apparatus for an electronic device as recited in claim 11, wherein said elastic member is a leaf spring, by which said cooling solid body is pressed onto the electronic device at the center thereof. ### Claim 13 A cooling apparatus for an electronic device, comprising: an electronic device to be cooled; highly viscous fluid layer containing thermal conductive powder provided on a heat transfer portion of said electronic device; a cooling solid body in close contact through said highly viscous fluid layer with the heat transfer portion of said electronic device, the close contact portion of said cooling solid body having multiple grooves open to the outside of said cooling solid body; and a spring member for pressing said cooling solid body on said electronic device and for pressing the highly viscous fluid layer constantly to keep the fluid layer as a thin layer. ### Claim 14 (depends on 13) A cooling apparatus for an electronic device as recited in claim 13, wherein said spring member is a leaf spring and the apparatus includes a load support means for transmitting an elastic load of the leaf spring to the center of said cooling solid body. ### Claim 15 A cooling apparatus for an electronic device, comprising: an electronic device of which a package contains at least one semiconductor chip; a cooling solid body for eliminating heat produced by said electronic device; highly viscous fluid layer containing thermal conductive powder with high thermal conductivity sandwiched between an overall heat transfer surface of said electronic device and a heat transfer surface of said cooling solid body; and spring means for providing an elastically pressing to force said cooling solid body into close contact with said electronic device and for pressing the fluid layer constantly so as to keep the fluid layer as a thin layer. ### Claim 16 A cooling apparatus for an electronic device, comprising: a multichip module in which a ceramic package hermetically seals a ceramic multilayer interconnection substrate with multiple LSI chips packaged thereon and flexible thermal conductive contactors transmit heat produced by said LSI chips to the ceramic package; a water-cooled jacket in close contact through highly viscous fluid layer containing thermal conductive powder and having high thermal conductivity and viscosity with the overall surface of a heat transfer portion of the multichip module, water passing through the interior of the water-cooled jacket; and means for providing an elastically pressing to force the water-cooled jacket into close contact with the multichip module in order to press said highly viscous fluid layer between the water-cooled jacket and the multichip module constantly to keep the fluid layer as a thin layer. ### Claim 17 (depends on 16) A cooling apparatus for an electronic device as recited in claim 16, wherein said elastically pressing means is a leaf spring, and the apparatus has an arrangement in which an elastic load of said leaf spring is transmitted to the center of said water-cooled jacket through a load support means. ### Claim 18 A cooling apparatus for an electronic device, comprising a multichip module package made of a high thermal conductive material to seal a ceramic multilayer interconnection substrate with multiple LSI chips packaged thereon and flexible thermal conductive contactors to transmit heat produced by said LSI chips to said package; multiple grooves provided on at least one of contact surfaces between heat transfer surfaces of said LSI chips and heat transfer surfaces of said flexible thermal conductive contactors; a highly viscous fluid layer containing thermal conductive powder sandwiched between said contact surfaces; and an elastic member operatively arranged for forcing said flexible thermal conductive contactors into close contact with the heat transfer surfaces of said LSI chips and for pressing said highly viscous fluid layer constantly to keep the fluid layer as a thin layer. ### Claim 19 (depends on 18) A cooling apparatus for an electronic device, as recited in claim 18, wherein said flexible conductive contactors include fins fitting with a number of flat fins extending from an inner surface of said package with microgaps, and said highly viscous mixture is also sandwiched between adjacent ones of said fins. ### Claim 20 (depends on 19) A cooling apparatus for an electronic device, as recited in claim 19, wherein each of said thermal conductors including the fins is formed with said multiple grooves on its surface in contact with said LSI chips. ### Claim 21 (depends on 18) A cooling apparatus for an electronic device, as recited in claim 18, wherein each of said flexible thermal conductive contactors is a triangular thermal conductor having a circular surface in contact with a corresponding V-shaped groove formed in an inner surface of said package and a flat surface in contact with the LSI chips, a number of grooves communicating with the outside are provided on said circular and flat surfaces of said thermal conductor, and highly viscous mixture is sandwiched between said circular surface and the package. ### Claim 22 A cooling apparatus for an electronic device, comprising a multichip module package made of a high thermal conductive material to seal a ceramic multilayer interconnection substrate with multiple microchip carriers containing LSI chips packaged thereon and flexible thermal conductive contactors to transmit heat produced by said LSI chips to said package; multiple grooves provided on one of contact surfaces between heat transfer surface of said microchip carriers and said flexible thermal conductive contactors; a highly viscous fluid layer containing thermal conductive powder sandwiched between the two contact surfaces; and an elastic member operatively arranged for forcing said flexible thermal conductive contactors into close contact with the heat transfer surface of said microchip carriers and for pressing said highly viscous fluid layer constantly to keep the fluid layer as a thin layer. ### Claim 23 (depends on 22) A cooling apparatus for an electronic device, as recited in claim 22, wherein said flexible thermal conductive contactors are thermal conductors including flat fins fitting with a number of flat fins extending from an inner surface of said package with microgaps, and said thermal conductors are provided with said multiple grooves on its surface in contact with the microchip carriers. ### Claim 24 (depends on 8) A cooling apparatus for an electronic device as recited in claim 8, wherein said transfer surface defines grid-shaped grooves so as to make the grooves communicate with each other. ### Claim 25 (depends on 24) A cooling apparatus for an electronic device as recited in claim 24, wherein the cooling solid body includes a through-hole extending from the heat transfer surface to the opposite surface of the cooling solid body, each of the grooves communicates with the through-hole so as to open to the outside of the cooling solid body and communicate with space surrounding said cooling solid body. ### Claim 26 (depends on 8) A cooling apparatus for an electronic device as recited in claim 8, wherein said transfer surface defines radially extending grooves and annular concentric grooves crossing said radially extending grooves so to make the grooves communicate with each other. ### Claim 27 (depends on 26) A cooling apparatus for an electronic device as recited in claim 26, wherein the cooling solid body includes a through-hole extending from the heat transfer surface to the opposite surface of the cooling solid body, each of the grooves communicates with the through-hole so as to open to the outside of the cooling solid body and communicate with space surrounding said cooling solid body. ### Claim 28 (depends on 8) A cooling apparatus for an electronic device as recited in claim 8, wherein said transfer surface defines multiple radially extending grooves so as to make the grooves communicate with each other. ### Claim 29 (depends on 28) A cooling apparatus for an electronic device as recited in claim 28, wherein the cooling solid body includes a through-hole extending from the heat transfer surface to the opposite surface of the cooling solid body, each of the grooves communicates with the through-hole so as to open to the outside of the cooling solid body and communicate with space surrounding said cooling solid body. ### Claim 30 (depends on 1) The cooling apparatus according to claim 1, wherein the thermal conductive powder constitutes fine particles of zinc oxide. ### Claim 31 (depends on 1) The cooling apparatus according to claim 1, wherein the thermal conductive powder constitutes fine particles of ceramic. ### Claim 32 (depends on 6) The cooling apparatus according to claim 6, wherein the thermal conductive powder constitutes fine particles of zinc oxide. ### Claim 33 (depends on 6) The cooling apparatus according to claim 6, wherein the thermal conductive powder constitutes fine particles of ceramic. ### Claim 34 (depends on 11) The cooling apparatus according to claim 11, wherein the thermal conductive powder constitutes fine particles of zinc oxide. ### Claim 35 (depends on 11) The cooling apparatus according to claim 11, wherein the thermal conductive powder constitutes fine particles of ceramic. ### Claim 36 (depends on 13) The cooling apparatus according to claim 13, wherein the thermal conductive powder constitutes fine particles of zinc oxide. ### Claim 37 (depends on 13) The cooling apparatus according to claim 13, wherein the thermal conductive powder constitutes fine particles of ceramic. ### Claim 38 (depends on 15) The cooling apparatus according to claim 15, wherein the thermal conductive powder constitutes fine particles of zinc oxide. ### Claim 39 (depends on 15) The cooling apparatus according to claim 15, wherein the thermal conductive powder constitutes fine particles of ceramic. ### Claim 40 (depends on 16) The cooling apparatus according to claim 16, wherein the thermal conductive powder constitutes fine particles of zinc oxide. ### Claim 41 (depends on 16) The cooling apparatus according to claim 16, wherein the thermal conductive powder constitutes fine particles of ceramic. ### Claim 42 (depends on 18) The cooling apparatus according to claim 18, wherein the thermal conductive powder constitutes fine particles of zinc oxide. ### Claim 43 (depends on 18) The cooling apparatus according to claim 18, wherein the thermal conductive powder constitutes fine particles of ceramic. ### Claim 44 (depends on 22) The cooling apparatus according to claim 22, wherein the thermal conductive powder constitutes fine particles of zinc oxide. ### Claim 45 (depends on 22) The cooling apparatus according to claim 22, wherein the thermal conductive powder constitutes fine particles of ceramic.