Flexible printed circuit board with embedded optical waveguide structure

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.