Patent ID: 8705908

Claim:
An optical transmission module comprising: an optical wiring for transmitting light; and an optical element for irradiating a light incidence plane of the optical wiring with light and a control circuit component for driving light emission of the optical element based on an externally input electric signal; or an optical element for receiving light emitted from a light emitting surface of the optical wiring and converting to an electric signal and a control circuit component for amplifying the electric signal output from the optical element and outputting to the outside; wherein a plurality of boards overlapped and stacked so as to form a step with each other is arranged; a first board stacked at one end in a stacking direction of the plurality of boards is mounted with the optical wiring and the optical element so as to sandwich both surfaces in the stacking direction, and a board surface on the first board side of a second board stacked at another end is mounted with the control circuit component; the plurality of boards includes the first board, the second board, and a third board arranged between the first board and the second board; and the third board is arranged to avoid the control circuit component.