Light-receiving package for flat-plate mounting, and optical module

A method of manufacturing a light-receiving package for flat-plate

• mounting, comprising, in order, the steps of:
• fabricating a first subassembly in which a photo diode is fixed to a front surface of a retaining holder, and a back surface of the retaining holder is a flat surface capable of moving parallel on a plane parallel to a light-receiving surface of the photo diode and fabricating a second subassembly which has a rectangular U-shaped concave holder for retaining the retaining holder and a flat-plate base disposed on a substrate and in which a surface of the flat-plate base that is mounted on the substrate is a flat surface capable of moving parallel to a substrate surface, and at least one of surfaces of the concave holder having a rectangular U-shape is a flat surface capable of moving parallel to the back surface of the retaining holder;
• fixing the second subassembly onto the substrate;
• performing optical alignment by bringing the back surface of the retaining holder of the first subassembly into contact with the one of the surfaces of the rectangular U-shaped concave holder of the second subassembly;
• and
• fixing the retaining holder and the rectangular U-shaped concave holder by spot welding at a position where predetermined reception sensitivity is obtained in the optical alignment step.