US 12,262,464 B2
Methods for forming engineered thermal paths of printed circuit boards by use of removable layers
Matthew D. Neely, Santa Ana, CA (US); Michael Len, Santa Ana, CA (US); and King Yip Leung, Santa Ana, CA (US)
Filed by TTM TECHNOLOGIES INC., Santa Ana, CA (US)
Filed on Dec. 6, 2021, as Appl. No. 17/543,512.
Claims priority of provisional application 63/123,400, filed on Dec. 9, 2020.
Prior Publication US 2022/0183141 A1, Jun. 9, 2022
Int. Cl. H05K 3/42 (2006.01); H05K 1/02 (2006.01); H05K 1/11 (2006.01); H05K 3/00 (2006.01)
CPC H05K 1/0206 (2013.01) [H05K 1/115 (2013.01); H05K 3/0026 (2013.01); H05K 3/0047 (2013.01); H05K 3/422 (2013.01); H05K 3/423 (2013.01); H05K 3/0038 (2013.01); H05K 2203/0542 (2013.01); H05K 2203/072 (2013.01); H05K 2203/0723 (2013.01); H05K 2203/1572 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method of forming a thermal and/or an electrical path in a PCB, the method comprising:
forming a first removable layer over a top surface of a PCB and a second removable layer over a bottom surface of the PCB;
milling or laser drilling through both the first removable layer and the PCB from the top surface to form a first cavity extending into the PCB;
seed plating the PCB including the first cavity with a first seed plating material to form a first conductive coating;
initial panel plating the PCB with a metal to partially fill the first cavity;
milling or laser drilling through both the second removable layer and the PCB from the bottom surface to form a second cavity extending into the PCB, the first cavity in a thermal communication and/or an electrical communication with the second cavity;
seed plating the PCB including the second cavity with a second seed plating material to form a second conductive coating;
panel plating the PCB with the metal to fully fill the first cavity and the second cavity and form a first plated metal layer on a first exposed surface of the PCB and a second plated metal layer on a second exposed surface of the PCB; and
removing the first and second removable layers from the PCB to form the PCB with a thermal and/or an electrical path comprising the first cavity and the second cavity filled with the metal, wherein a cross sectional area of the filled first cavity or the filled second cavity larger than a cross sectional area of through-vias.