Optical module circuit board having flexible structure

An optical module circuit board comprising a flexible printed circuit having at least a multilayered structure in which a layer containing a conductive metal interconnection is sandwiched between insulating layers,

• wherein said flexible printed circuit includes:
• a main body portion having said multilayered structure, a first surface mounted with an electronic component, and a second surface which opposes said first surface and is in contact with and entirely covered with a first auxiliary plate;
• a neck portion having said multilayered structure, extending from one end of said main body portion, and having a first surface continuously extending from said first surface of said main body portion, and a second surface continuously extending from said second surface of said main body portion;
• and
• a head portion positioned at a distal end of said neck portion extending from said one end of said main body portion having said multilayered structure, and mounted with an optical operation element, said head portion having a first surface continuously extending from said first surface of said neck portion, and a second surface which continuously extends from said second surface of said neck portion, and is in contact with and entirely covered with a second auxiliary plate, said second auxiliary plate physically spaced apart from said first auxiliary plate,
• said neck portion holds said head portion so as to set said first surface of said head portion on a plane different from a plane coplanar with said first surface of said main body portion, and
• said second surface of said neck portion is exposed between said first auxiliary plate and said second auxiliary plate.

An optical module circuit board comprising a flexible printed circuit having at least a multilayered structure in which a layer containing a conductive metal interconnection is sandwiched between insulating layers,

• wherein said flexible printed circuit includes:
• a head portion having said multilayered structure, a power supply filter circuit with a bypass capacitor mounted on a first surface, and an optical operation element mounted on a second surface opposite to said first surface;
• and
• a terminal portion having said multilayered structure, extending from one end of said head portion, and having a first surface continuously extending from said first surface of said head portion, and a second surface continuously extending from said second surface of said head portion.