Subminiature optical transmission module and method for manufacturing same by using semiconductor packaging scheme

An optical transmission module comprising:

• a mold body having a first surface and a second surface opposite to each other;
• a plurality of edge-type light emitting elements, each of which is molded inside the first surface of the mold body and generates an optical signal in the edge direction of a chip;
• an arrayed waveguide grating (AWG) which is molded in the first surface of the mold body and includes, on one side thereof, a plurality of input waveguides corresponding to the plurality of edge-type light emitting elements, and optically multiplexes a plurality of optical signals incident through the plurality of input waveguides and outputs same through an output waveguide, and
• a wiring layer formed of an insulating material on the first surface of the mold body, wherein
• the AWG is molded inside the first surface of the mold body without top cladding with the input waveguide, and
• the wiring layer is formed of an insulating material on the first surface of the mold body including the upper parts of the cores of a plurality of input waveguides, thereby serving as top cladding to the input waveguides.

A method of manufacturing an optical transmission module, the method comprising the steps of:

• attaching a light emitting element is applied, and an arrayed waveguide grating (AWG) in which a top cladding of an input waveguide is not formed so as to match the height of the optical axis of the AWG with that of the light emitting element to predetermined positions on a carrier on which an adhesive;
• forming a molding layer on top of the carrier with an epoxy mold compound (EMC) and flattening the surface after curing;
• after performing a chemical mechanical polishing (CMP) process on the upper surface of the cured mold, obtaining a mold body having a first surface and a second surface facing each other by separating the cured mold and the carrier;
• exposing the first surface in which a terminal pad of the light emitting element and a core of an input waveguide of the AWG are located by inverting the mold body;
• and
• forming a wiring layer made of an insulating material on the first surface of the mold body, wherein
• the wiring layer formed on top of the core of the input waveguide uses a material having a lower refractive index than the core of the input waveguide to serve as the top cladding of the input waveguide.