# US 2021/0243880 A1 · Printed circuit board assemblies with engineered thermal paths and methods of manufacture > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0243880 A1 - Document ID: US20210243880A1 - Status: Published application - Kind: A1 - Application number: 17/162,773 - Filed: 2021-01-29 - Published: 2021-08-05 - Earliest claimed: 2020-01-31 - Assignees: Anaren, Inc. - Applicants: Anaren, Inc. - Inventors: Rick Bauer; Jerrad Martinson; Shane Hoffstatter; Doyle Laudal; Mike Lugert; Mike Len - Web page: https://patentgrep.com/patent/US20210243880A1 ## CPC - H05K 1/0203: {Cooling of mounted components (H05K1/0272 takes precedence)} - H05K 1/0204: {using means for thermal conduction connection in the thickness direction of the substrate (H05K1/0207 takes precedence)} - H05K 3/4076: {by thin-film techniques} - H05K 1/0206: {by printed thermal vias} - H05K 2201/09563: Metal filled via - H05K 2201/09845: Stepped hole, via, edge, bump or conductor - H05K 2203/025: Abrading, e.g. grinding or sand blasting - H05K 2203/0723: Electroplating, e.g. finish plating - H05K 2203/1476: Same or similar kind of process performed in phases, e.g. coarse patterning followed by fine patterning - H05K 2203/1572: Processing both sides of a PCB by the same process; Providing a similar arrangement of components on both sides; Making interlayer connections from two sides - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS ## Abstract A printed circuit board (PCB) having an engineered thermal path and a method of manufacturing are disclosed herein. In one aspect, the PCB includes complementary cavities formed on opposite sides of the PCB. The complementary cavities are in a thermal communication and/or an electrical communication to form the engineered thermal path and each cavity is filled with a thermally conductive material to provide a thermal pathway for circuits and components of the PCB. The method of manufacturing may further include drilling and/or milling each cavity, panel plating the cavities and filling the cavities with a suitable filling material. ## Claims ### Claim 1 A printed circuit board (PCB) having an engineered thermal, an electrical path, or both; the PCB comprising: one or more layers; a first cavity in a top surface of the printed circuit board, wherein the first cavity is filled with a first thermal conductive material; a second cavity in a bottom surface of the printed circuit board, wherein the second cavity is filled with a second thermal conductive material; and, wherein the first cavity is in thermal communication, electrical communication, or both thermal and electrical communication with the second cavity to form a filled cavity structure as an engineered thermal path, an electrical path or both. ### Claim 2 (depends on 1) The printed circuit board of claim 1, wherein the second cavity has same dimensions as the first cavity. ### Claim 3 (depends on 1) The printed circuit board of claim 1, wherein the second cavity has different dimensions than the first cavity. ### Claim 4 (depends on 1) The printed circuit board of claim 1, wherein the first cavity is adjoining with the second cavity. ### Claim 5 (depends on 1) The printed circuit board of claim 1, wherein the first thermal conductive material and the second conductive thermal material are selected from a group consisting of copper, silver, gold, aluminum, and nickel. ### Claim 6 (depends on 1) The printed circuit board of claim 1, further comprising one or more plated or filled vias at discrete locations. ### Claim 7 (canceled) ### Claim 8 (depends on 1) A printed circuit board (PCB) assembly comprising the PCB of claim 1, the PCB assembly comprising: surface mount technology (SMT) components mounted on a first side of the PCB. ### Claim at position 9 9-10. (canceled) ### Claim 11 (depends on 8) The printed circuit board assembly of claim 8, wherein the second cavity has a greater cross-sectional area than the first cavity. ### Claim 12 A method for forming a printed circuit board having an engineered thermal path, the method comprising: forming a first cavity in a top surface of the printed circuit board; filling the first cavity with a first thermal conductive material; forming a second cavity in a bottom surface of the printed circuit board, wherein the first cavity is in thermal communication, electrical communication, or both thermal and electrical communication with the second cavity to form a filled cavity structure as an engineered thermal path, an electrical path, or both; and, filling the second cavity with a second thermal conductive material. ### Claim 13 (depends on 12) The method of claim 12, further comprising forming the first cavity and second cavity by drilling, milling, or a combination thereof. ### Claim 14 (depends on 12) The method of claim 12, wherein the second cavity is formed to have different dimensions or a greater cross-sectional area than the first cavity. ### Claim 15 (depends on 12) The method of claim 12, wherein the second cavity is formed to have same dimensions as the first cavity. ### Claim 16 (depends on 12) The method of claim 12, comprising panel plating the first cavity prior to filling the first cavity and panel plating the second cavity prior to filling the second cavity. ### Claim 17 (depends on 12) The method of claim 12, wherein the second cavity is formed to be adjoining with the first cavity. ### Claim 18 (depends on 12) The method of claim 12, further comprising planarizing at least one of the top surface and the bottom surface. ### Claim 19 (depends on 12) The method of claim 12, wherein the first thermal conductive material and the second conductive thermal material are selected from a group consisting of copper, tin, gold, silver, nickel, aluminum, conductive polymers, conductive epoxies, non-conductive polymers, and combinations thereof. ### Claim 20 (depends on 12) The method of claim 12, wherein the first thermal conductive material and the second conductive thermal material have a same composition or different compositions. ### Claim 21 A method for forming a printed circuit board having an engineered thermal path, the method comprising: forming a first cavity in a top surface of the printed circuit board (PCB); panel plating the PCB and the first cavity; forming a second cavity in a bottom surface of the printed circuit board; applying a photoresist mask to the PCB to expose the first cavity and the second cavity; and simultaneously plating to fill the first cavity and the second cavity with a thermal conductive material, wherein the first cavity is in thermal communication, electrical communication, or both thermal and electrical communication with the second cavity to form a filled cavity structure as an engineered thermal path, an electrical path, or both. ### Claim 22 (canceled) ### Claim 23 (depends on 21) The method of claim 21, wherein the second cavity is formed to have different dimensions or a greater cross-sectional area than the first cavity. ### Claim 24 (depends on 21) The method of claim 21, wherein the second cavity is formed to have same dimensions as the first cavity. ### Claim at position 24 25-30. (canceled)