# US 2017/0257977 A1 · Thermal interface adhesion for transfer molded electronic components > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0257977 A1 - Document ID: US20170257977A1 - Status: Published application - Kind: A1 - Application number: 15/060,137 - Filed: 2016-03-03 - Published: 2017-09-07 - Earliest claimed: 2016-03-03 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Timothy J. Chainer; Michael A. Gaynes - Web page: https://patentgrep.com/patent/US20170257977A1 ## CPC - H05K 3/30: Assembling printed circuits with electric components, e.g. with resistors - B29C 45/14655: {connected to or mounted on a carrier, e.g. lead frame} - B29C 45/372: {provided with means for marking or patterning, e.g. numbering articles} - H05K 1/0209: {External configuration of printed circuit board adapted for heat dissipation, e.g. lay-out of conductors, coatings} - H05K 1/185: associated with components encapsulated in the insulating substrate of the PCBs; associated with components incorporated in internal layers of multilayer circuit boards - H05K 3/284: {for encapsulating mounted components (H05K1/185 takes precedence)} - H10W 40/22: characterised by their shape, e.g. having conical or cylindrical projections - H10W 40/70: Fillings or auxiliary members in containers or in encapsulations for thermal protection or control - H10W 74/016: {using moulds} - H05K 2201/10977: Encapsulated connections - H05K 2203/1316: Moulded encapsulation of mounted components - H10W 40/258: {Metallic materials (H10W40/254, H10W40/257, H10W40/255, H10W40/251, H10W40/253 take precedence)} - H10W 40/43: by flowing gases, e.g. forced air cooling - H10W 40/47: by flowing liquids, e.g. forced water cooling - H10W 70/698: Semiconductor materials that are electrically insulating, e.g. undoped silicon - H10W 74/00: Encapsulations, e.g. protective coatings - H10W 74/10: characterised by their shape or disposition - H10W 74/114: {by a substrate and the encapsulations} - Y10T 29/4913: Assembling to base an electrical component, e.g., capacitor, etc. - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An electronic component to be encapsulated is introduced into a mold cavity. The mold cavity includes at least first and second halves, and at least one of the halves is formed with a negative of a thermal-interface-material engaging pattern thereon. An encapsulating material, which encapsulates the electronic component and engages the negative of the thermal-interface-material engaging pattern, is introduced into the mold cavity. The encapsulating material is allowed to solidify such that a thermal-interface-material engaging surface of the encapsulant solidifies with the thermal-interface-material engaging pattern thereon. During subsequent assembly, the thermal-interface-material engaging pattern engages thermal interface material to resist lateral motion of the thermal interface material. ## Claims ### Claim 1 A method comprising: introducing into a mold cavity an electronic component to be encapsulated, said mold cavity comprising at least first and second halves, at least one of said halves being formed with a negative of a thermal-interface-material engaging pattern thereon; introducing into said mold cavity an encapsulating material which encapsulates said electronic component and engages said negative of said thermal-interface-material engaging pattern; and allowing said encapsulating material to solidify such that a thermal-interface-material engaging surface of said encapsulant solidifies with said thermal-interface-material engaging pattern thereon. ### Claim 2 (depends on 1) The method of claim 1, further comprising: mounting said electronic component on a printed circuit board; and securing a heat sink to said electronic component on said printed circuit board with a thermal interface material intermediate said heat sink and said thermal-interface-material engaging pattern of said solidified encapsulating material such that said thermal-interface-material engaging pattern engages said thermal interface material to resist lateral motion of said thermal interface material. ### Claim 3 (depends on 2) The method of claim 2, wherein said steps are carried out without wiping the thermal-interface-material engaging surface with alcohol, without abrading the thermal-interface-material engaging surface, without exposing the thermal-interface-material engaging surface to a plasma cleaning process, without exposing the thermal-interface-material engaging surface to ultraviolet light, and without exposing the thermal-interface-material engaging surface to ozone. ### Claim 4 (depends on 2) The method of claim 2, wherein, in said securing step, said thermal interface material comprises at least one of thermal grease, thermal putty, and thermal gel. ### Claim 5 (depends on 1) The method of claim 1, wherein, in said step of introducing said electronic component into said mold cavity, said encapsulating material comprises a release agent. ### Claim 6 (depends on 5) The method of claim 5, wherein in said step of allowing said encapsulating material to solidify, said thermal-interface-material engaging surface has a surface energy less than thirty five ergs per square centimeter. ### Claim 7 (depends on 1) The method of claim 1, wherein, in said step of introducing said electronic component into said mold cavity, said thermal-interface-material engaging pattern has an average roughness of at least three microns. ### Claim 8 (depends on 1) The method of claim 1, wherein, in said step of introducing said electronic component into said mold cavity, said thermal-interface-material engaging pattern comprises at least one of a diamond pattern and a channel pattern. ### Claim 9 A method comprising: providing an encapsulated electronic component mounted on a printed circuit board, said encapsulated electronic component having an outward-facing thermal-interface-material engaging pattern on an encapsulant thereof; and securing a heat sink to said encapsulated electronic component on said printed circuit board with a thermal interface material intermediate said heat sink and said thermal-interface-material engaging pattern of said encapsulant such that said thermal-interface-material engaging pattern engages said thermal interface material to resist lateral motion of said thermal interface material. ### Claim 10 (depends on 9) The method of claim 9, wherein, in said securing step, said thermal interface material comprises at least one of thermal grease, thermal putty, and thermal gel. ### Claim 11 (depends on 9) The method of claim 9, wherein, in said providing step, said encapsulating material comprises a release agent and said thermal-interface-material engaging pattern has a surface energy less than thirty five ergs per square centimeter. ### Claim 12 (depends on 9) The method of claim 9, wherein said steps are carried out without wiping the thermal-interface-material engaging pattern with alcohol, without abrading the thermal-interface-material engaging pattern, without exposing the thermal-interface-material engaging pattern to a plasma cleaning process, without exposing the thermal-interface-material engaging pattern to ultraviolet light, and without exposing the thermal-interface-material engaging pattern to ozone. ### Claim 13 (depends on 9) The method of claim 9, wherein, in said providing step, said thermal-interface-material engaging pattern has an average roughness of at least three microns. ### Claim 14 (depends on 9) The method of claim 9, wherein, in said providing step, said thermal-interface-material engaging pattern comprises at least one of a diamond pattern and a channel pattern. ### Claim 15 An assembly comprising: a printed circuit board; an encapsulated electronic component mounted on said printed circuit board, said encapsulated electronic component in turn comprising an encapsulant with an outward-facing thermal-interface-material engaging pattern thereon; a heat sink; and a thermal interface material intermediate said heat sink and said thermal-interface-material engaging pattern of said encapsulant; wherein said heat sink is assembled to said printed circuit board such that said thermal-interface-material engaging pattern engages said thermal interface material to resist lateral motion of said thermal interface material. ### Claim 16 (depends on 15) The assembly of claim 15, wherein said thermal interface material comprises at least one of thermal grease, thermal putty, and thermal gel. ### Claim 17 (depends on 15) The assembly of claim 15, wherein said encapsulant comprises a release agent and said outward-facing thermal-interface-material engaging pattern has a surface energy less than thirty five ergs per square centimeter. ### Claim 18 (depends on 15) The assembly of claim 15, wherein said outward-facing thermal-interface-material engaging pattern has an average roughness of at least three microns. ### Claim 19 (depends on 15) The assembly of claim 15, wherein said thermal-interface-material engaging pattern has a draft angle of at least one degree from vertical. ### Claim 20 (depends on 15) The assembly of claim 15, wherein said thermal-interface-material engaging pattern comprises at least one of a diamond pattern and a channel pattern.