US 12,446,149 B2
Flexible printed circuit board with embedded optical waveguide structure
Chia-Fu Hsu, Hsinchu (TW); and Chun-Yen Chen, Hsinchu (TW)
Assigned to CYNTEC CO., LTD., Hsinchu (TW)
Filed by CYNTEC CO., LTD., Hsinchu (TW)
Filed on Sep. 26, 2023, as Appl. No. 18/373,263.
Prior Publication US 2025/0106987 A1, Mar. 27, 2025
Int. Cl. H05K 1/02 (2006.01); H05K 3/00 (2006.01); H05K 3/18 (2006.01); H05K 3/40 (2006.01)
CPC H05K 1/028 (2013.01) [H05K 3/0094 (2013.01); H05K 3/188 (2013.01); H05K 3/4007 (2013.01); H05K 2201/0367 (2013.01); H05K 2201/09985 (2020.08); H05K 2201/10121 (2013.01)] 25 Claims
OG exemplary drawing
 
1. A flexible printed circuit board with embedded optical waveguide structure, comprising at least one photoelectric transmission unit, wherein each said photoelectric transmission unit comprises:
a flexible insulation layer;
a first optoelectronic unit embedded in said photoelectric transmission unit and configured to convert electrical signal into optical signal;
a second optoelectronic unit embedded in said photoelectric transmission unit and configured to convert optical signal into electrical signal;
at least one redistribution layer having at least one conductive structure stacked with said flexible insulation layer and electrically connected with said first optoelectronic unit and said second optoelectronic unit;
an optical waveguide structure stacked with said flexible insulation layer for transmitting optical signal;
a first metal bump adjacent to said optical waveguide structure and in optical alignment with said first optoelectronic unit to provide a reflection plane for optical signal;
a second metal bump adjacent to said optical waveguide structure and in optical alignment with said second optoelectronic unit to provide a reflection plane for optical signal; and
a first flexible cover layer covering on said first metal bump, said second metal bump and said optical waveguide structure;
wherein said first metal bump and said second metal bump are solid structures made of the same material as the one of said redistribution layer.